A widen­ing dis­tance between per­spect­ives about Don­ald Trump among Republicans and all oth­er voters—the “Trump gap”—presents GOP lead­ers with a conun­drum as the primar­ies ap­proach.

The phe­nomen­on can be charted across a series of na­tion­al polls, from which a con­sist­ent pat­tern has emerged in at­ti­tudes to­ward the GOP front-run­ner since he entered the race last sum­mer.

Re­pub­lic­an par­tis­ans and some oth­er con­ser­vat­ive-lean­ing con­stitu­en­cies are demon­strably warm­ing in their at­ti­tudes to­ward the blustery busi­ness ex­ec­ut­ive. But views of Trump gen­er­ally re­main stag­nant, or are even de­teri­or­at­ing, among adults who identi­fy as Demo­crats or in­de­pend­ents. With­in that mix, the groups at the core of the co­ali­tion that powered Pres­id­ent Obama’s two vic­tor­ies ex­press es­pe­cially tox­ic opin­ions about him.

The dy­nam­ic sug­gests that more Re­pub­lic­ans are grow­ing com­fort­able with the pro­spect of Trump win­ning the party nom­in­a­tion, even as res­ist­ance to him is solidifying among the voters he would need to win the gen­er­al elec­tion.

“Re­pub­lic­ans are look­ing at him and start­ing to think, ‘Maybe I could swal­low him,’ and independents  are look­ing at him go­ing, ‘Oh my god, I can’t be­lieve it,’” said the poll­ster for one of Trump’s rivals for the nom­in­a­tion, who asked to re­main anonymous to dis­cuss the race’s in­tern­al dy­nam­ics.

What makes this pat­tern es­pe­cially fraught for GOP strategists is that Hil­lary Clin­ton, the overwhelming  fa­vor­ite for the Demo­crat­ic nomination, also faces very sticky negative perceptions among voters out­side of her par­tis­an base. Yet for all of Clin­ton’s dif­fi­culties with in­de­pend­ent voters and oth­er swing con­stitu­en­cies, Trump’s stand­ing among the same groups usu­ally ranks lower in the same polls.

If Trump wins the nom­in­a­tion, Re­pub­lic­ans will be ex­posed to the risk that Clinton can mo­bil­ize a win­ning co­ali­tion even without resolv­ing voters’ con­cerns about her, simply be­cause they find the al­tern­at­ive even less ac­cept­able.

“Hil­lary is not go­ing to have the same kind of pos­it­ive pull and trac­tion that Obama did, es­pe­cially in 2008,” says Alan Ab­ramow­itz, a political scientist at Emory Uni­versity . “So the mo­bil­iz­a­tion will be based more on anti-Trump or possibly anti-Ted Cruz kind of ap­peals.”

Across mul­tiple na­tion­al sur­veys, Trump’s im­prov­ing im­age among Re­pub­lic­ans since last sum­mer is con­sist­ent and dra­mat­ic. In CNN/ORC polls, the share of Re­pub­lic­ans ex­press­ing a fa­vor­able view of Trump has spiked from 51 per­cent in Ju­ly to 71 per­cent in Decem­ber. In Quin­nipi­ac Uni­versity sur­veys, Re­pub­lic­an favorability to­ward Trump has soared from 34 per­cent in May to 63 per­cent in Decem­ber. The NBC/Wall Street Journ­al poll has showed more mod­est gains, but even there, Trump’s fa­vor­ab­il­ity rat­ing among likely GOP primary voters has increased from 44 per­cent in Ju­ly to 51 per­cent last month.

The mag­nitude of the change among Re­pub­lic­ans is even more ap­par­ent when con­sid­er­ing Trump’s net fa­vor­ab­il­ity: that is, the dif­fer­ence between the share of Re­pub­lic­ans who view him fa­vor­ably and un­fa­vor­ably. In the CNN/ORC poll, Trump’s net fa­vor­ab­il­ity has jumped from 9 to 43 per­cent­age points; in Quinnipiac polls, he’s moved from a net neg­at­ive rat­ing of 18 points to a net positive of 33; and even in the NBC/WSJ sur­vey, his net pos­it­ive rat­ing has nearly tripled from 9 to 25 per­cent­age points.

Alex Cas­tel­lanos, a long-time GOP me­dia con­sult­ant who has not en­dorsed a 2016 can­did­ate, says Trump has strengthened his stand­ing in­side the party so dra­mat­ic­ally be­cause he “has tapped in­to the Re­pub­lic­an soul”—par­tic­u­larly the fear that the coun­try is ir­re­vers­ibly chan­ging un­der Obama.

“With Re­pub­lic­ans, I think he [em­bod­ies the say­ing that] ‘des­per­ate people do des­per­ate things,’” Cas­tel­lanos said. “We like him be­cause maybe we see him as our last shot to re­pair this coun­try. How has he done it? By ant­ag­on­iz­ing every adversary of the Re­pub­lic­an base. And in do­ing that he’s ce­men­ted him­self as the lead­er of our quest.”

But with adults bey­ond the Re­pub­lic­an co­ali­tion, Trump’s po­s­i­tion re­mains much more stable—and pre­cari­ous.

The share of in­de­pend­ents with a fa­vor­able view of Trump in­creased only from 39 per­cent in Ju­ly to 40 per­cent in Decem­ber in the CNN/ORC poll; in the NBC/WSJpoll, his fa­vor­able rat­ings among in­de­pend­ents have de­clined from 23 per­cent in Ju­ly to 18 per­cent in Decem­ber. Only in the Quin­nipi­ac poll has Trump’s stand­ing im­proved among in­de­pend­ents from 20 per­cent ex­press­ing a fa­vor­able view in May to a still mea­ger 32 per­cent today. In all three polls, the share of in­de­pend­ents ex­press­ing un­fa­vor­able views of Trump ex­ceeds the portion rat­ing him fa­vor­ably by at least 17 per­cent­age points.

As for cros­sov­er ap­peal, Trump’s fa­vor­ab­il­ity rat­ing among Demo­crats since last sum­mer re­mained vir­tu­ally un­changed in the Quin­nipi­ac and CNN/ORC surveys, and has slipped slightly in the NBC/WSJ poll.  In both the Decem­ber Quin­nipi­ac and NBC/WSJ polls few­er than one in 10 Demo­crats ex­pressed a favorable view to­ward Trump; in the CNN/ORC poll the num­ber is about one in eight.

The best-case scen­ario for Trump if he wins the GOP nom­in­a­tion is that, just as sus­tained ex­pos­ure to him has im­proved his po­s­i­tion among Re­pub­lic­ans, months of cam­paign­ing as the party’s choice could al­low him to burn­ish his im­age with oth­er voters. Watch­ing Trump’s con­tin­ued suc­cess in the primar­ies, some Republicans who were ini­tially skep­tic­al of him are be­gin­ning to en­ter­tain that pos­sib­il­ity.

That’s demon­strated by the sur­pris­ing case of Cas­tel­lanos, a long­time GOP media con­sult­ant. Cas­tel­lanos ac­know­ledges that earli­er in the cam­paign, he sought fund­ing from GOP donors to mount an ad­vert­ising cam­paign against Trump in the primar­ies be­cause he feared the bil­lion­aire would hurt the party if he won the nom­in­a­tion. But Cas­tel­lanos says he found little in­terest in such an effort.

Now he says that while he still be­lieves oth­er can­did­ates—par­tic­u­larly Senator Marco Ru­bio—would stand a bet­ter chance of win­ning in Novem­ber, he does not consider it im­possible for Trump to pre­vail. “I don’t think he’s the kind of president we need,” Cas­tel­lanos said. “But I don’t think he is un­elect­able.”

Cas­tel­lanos ac­know­ledges Trump would be­gin the gen­er­al elec­tion as an underdog against Hil­lary Clin­ton. But Cas­tel­lanos be­lieves Trump would move ag­gress­ively to court the voters now du­bi­ous of him—and could en­joy more success than most people ex­pect. “He will pivot,” said Cas­tel­lanos. “I would not be sur­prised if in the gen­er­al elec­tion we would see a very dif­fer­ent Trump. … Has he hurt him­self with His­pan­ics, minor­it­ies, wo­men, Demo­crats? Of course. Has he ir­re­par­ably lost his abil­ity to change how he is un­der­stood by them? Ab­so­lutely not.”

But many oth­er ana­lysts in­side and out­side the GOP are skep­tic­al that Trump could sub­stan­tially im­prove his im­age in a gen­er­al elec­tion be­cause many of the same policy po­s­i­tions and com­bat­ive per­son­al­ity traits that are at­tract­ing more Re­pub­lic­ans are pre­cisely the factors ali­en­at­ing oth­er voters.

Cit­ing such Trump pro­pos­als as mass de­port­a­tion of un­doc­u­mented im­mig­rants and a tem­por­ary ban on Muslims en­ter­ing the U.S., Emory Uni­versity’s Ab­ramow­itz says, “The reas­on he is do­ing bet­ter among Re­pub­lic­ans is that his message res­on­ates with a large share of the Re­pub­lic­an elect­or­ate; they agree with what he is pro­pos­ing. But out­side of the Re­pub­lic­an elect­or­ate those are things that are quite un­pop­u­lar. So I don’t think there is much room for growth in his stand­ing among [oth­er] groups at all.”

Gen­er­ally, across the three polls, Trump has es­tab­lished a some­what bet­ter image among men, and older adults near­ing the end of their work ca­reers (those aged 50 to 64), a group that has ex­pressed enorm­ous anxi­ety about their economic pro­spects in oth­er sur­veys.

Trump’s im­age re­mains es­pe­cially tox­ic among the com­pon­ents of the “co­ali­tion of the as­cend­ant”—the groups at the core of the mod­ern Demo­crat­ic co­ali­tion that are all in­creas­ing as a share of the elect­or­ate. Sup­port from those grow­ing groups—par­tic­u­larly the mil­len­ni­al gen­er­a­tion, minor­it­ies, and col­lege-edu­cated, single and sec­u­lar whites, es­pe­cially wo­men—al­lowed Obama to win two sol­id vic­tor­ies, des­pite fa­cing his­tor­ic de­fi­cits among oth­er whites.

Both the CNN and NBC/WSJ polls show Trump fa­cing un­fa­vor­able rat­ings from nearly 75 per­cent of non­white adults; about two-thirds of those ages 18 to 34; about two-thirds of col­lege gradu­ates; and just over three-fifths of wo­men. With those groups, Quin­nipi­ac gen­er­ally re­por­ted even slightly worse res­ults for Trump. And even those num­bers are in­flated by the warm­er at­ti­tudes to­ward him among Re­pub­lic­an par­tis­ans in all of those groups.

Fig­ures provided by CNN polling dir­ect­or Jen­nifer Agi­esta, for in­stance, show that while 66 per­cent of Re­pub­lic­an wo­men ex­pressed a fa­vor­able view of Trump in the Decem­ber sur­vey that plummeted to a minus­cule 12 per­cent among all women who are not Re­pub­lic­ans. Fully 81 per­cent of non-Re­pub­lic­an wo­men viewed Trump un­fa­vor­ably.

“We will have a gender gap that looks like the Grand Canyon if we have Trump vs. Hil­lary,” pre­dicts the poll­ster for an­oth­er Re­pub­lic­an pres­id­en­tial can­did­ate.

That pro­spect is es­pe­cially frus­trat­ing for Re­pub­lic­an strategists be­cause Clinton’s own fa­vor­ab­il­ity rat­ings with wo­men—and al­most all oth­er constituencies—have re­mained de­cidedly equi­voc­al for months. The share of all voters view­ing her fa­vor­ably stands at 47 per­cent in the latest CNN/ORC poll, 43 per­cent in Quin­nipi­ac, and only 37 per­cent in the NBC/WSJ poll. In each case, a lar­ger share of voters view her un­fa­vor­ably; and in each in­stance, her num­bers have hardly budged since last sum­mer.

Even some core Demo­crat­ic groups re­gister luke­warm (at best) feel­ings about Clin­ton. She draws fa­vor­able rat­ings from only just about half of wo­men in the CNN and Quin­nipi­ac sur­veys, and only about two-fifths of them in the NBC/WSJ poll. And, just as with Trump, even those mod­est num­bers are in­flated by her strong show­ing among wo­men in her own party. While 83 per­cent of Demo­crat­ic wo­men viewed Clin­ton fa­vor­ably in the latest CNN sur­vey, only 23 per­cent of non-Demo­crat­ic wo­men agreed. Only 19 per­cent of non-Demo­crat­ic men expressed fa­vor­able views of Clin­ton in the CNN poll.

Yet Clin­ton’s rat­ings look much bet­ter when com­pared to Trump’s. While a higher per­cent­age of men in all three polls ex­press fa­vor­able views to­ward Trump than Clin­ton, she en­joys a much wider ad­vant­age (of about 20 per­cent­age points or more) among wo­men in each sur­vey. She is viewed fa­vor­ably by far more Millennials, who this year will equal baby boomers as a share of eli­gible voters for the first time. Her over­all fa­vor­ab­il­ity rat­ing ex­ceeds his by 8 per­cent­age points in the CNN/ORC poll and ten points in both the NBC/WSJ and Quin­nipi­ac sur­veys.

A race between two can­did­ates la­bor­ing un­der such cloudy pub­lic as­sess­ments might turn on which could do more to re­verse the neg­at­ive judg­ments evid­ent today. But it might also prove a uniquely neg­at­ive and bruis­ing con­test de­cided by which con­test­ant can more ef­fect­ively re­in­force the gap between their op­pon­ent’s strong stand­ing among their par­tis­ans—and far more tenu­ous po­s­i­tion with everyone else.

This post appears courtesy of National Journal.