This article is from the archive of our partner National Journal

The question of the moment—as the competitive GOP field grows larger by the day—is why Hillary Clinton is barely being challenged for the Democratic nomination. And the answer lies within the changing nature of her party.

It's not because she's capable of raising record sums of money. After all, Jeb Bush has the same fundraising prowess, but he's hardly a shoo-in to be the GOP's presidential standard-bearer.

It's not because she's a Clinton. After all, voters are expressing a clear desire for change, and her last name is a reminder of the past. It certainly didn't help her much the last time she ran for president.

It isn't because she's a strong campaigner. As Jason Zengerle pointed out in a masterful New York magazine profile of her elective record, she has long shown a tin ear for politics and has underwhelmed in past campaigns.

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And it's not primarily because the Democrats have a fairly weak bench of presidential prospects—even though that's an important contributing factor. After all, there would be plenty of politicians who would consider running for president if Clinton didn't want to. Every senator, as the saying goes, looks in the mirror and sees a future president. Bloomberg's Jonathan Bernstein listed 16 plausible candidates other than Clinton in a recent column.

No, the main reason why Clinton is a near-lock for the nomination is that Democrats have become the party of identity. They're now dependent on a coalition that relies on exciting less-reliable voters with nontraditional candidates. President Obama proved he could turn out African-American, Hispanic, and young voters to his side in 2012 even as they faced particularly rough economic hardships during a weak recovery. As the first female major-party nominee for president, Clinton hopes to win decisive margins with women voters and is planning to run on that historic message—in sharp contrast to her campaign's argument playing down that uniqueness in 2008.

It's part of why freshman Sen. Elizabeth Warren inspires excitement from the party's grassroots, but former Maryland Gov. Martin O'Malley, whose progressive record in office set liberal benchmarks, isn't even polling at 1 percent nationally. It's why Sherrod Brown, a populist white male senator from a must-win battleground state is an afterthought in the presidential sweepstakes. It's why Virginia Sen. Tim Kaine, a runner-up to be Obama's running mate in 2008, quickly jumped on the Clinton bandwagon instead of pursuing any national ambitions. On Bernstein's list of 16 possible challengers, 15 are white and nine are white males. That makes many of them untenable standard-bearers in the modern Democratic Party.

Just look at the party's (few) competitive Senate primaries of recent vintage for an illustration of this dynamic. New Jersey Sen. Cory Booker, whose tenure as Newark mayor drew considerable scrutiny and occasional mockery, coasted to victory in a 2013 special election primary against Rep. Frank Pallone, a respected 25-year veteran of the House who had been angling for a promotion for many years. With Democrats lacking a single African-American senator at the time, Booker's election to the Senate was fait accompli.

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The 2014 Hawaii primary between appointed Sen. Brian Schatz and then-Rep. Colleen Hanabusa hinged on issues of ethnic identity, pitting a white candidate against one who is Japanese-American (and was backed by the widow of the late longtime Sen. Daniel Inouye). Schatz, despite holding an advantage as the incumbent, only eked out a victory by 1,782 votes despite a lockstep liberal record and support from national liberal groups. (Asian-Americans comprise a 38 percent plurality of Hawaii residents; whites make up 27 percent.)

This year, the Democratic primary royale will be taking place in Maryland, where Rep. Chris Van Hollen, who is white, is pitted against Rep. Donna Edwards, who is African-American. Both are reliable progressives, but Van Hollen has held more prominent leadership positions. She has been playing up their differences on several issuesentitlement reform, most significantly—but the real contrast for voters will be on race. In a state where nearly half of the Democratic primary electorate is African-American, Edwards is betting she'll have a strong floor of support, regardless of what happens in the campaign.

In the not-too-distant past, Van Hollen's credentials as a former Democratic Congressional Campaign Committee chairman, ranking Democrat on the Budget Committee, and on the fast-track within House leadership would make him a solid favorite for the nomination. But Edwards, who was just elected in 2008 and defeated a Democratic incumbent to do so, is betting on the power of identity to overcome her lack of experience. Senate Minority Leader Harry Reid's early endorsement of Van Hollen will mean little compared with the support Edwards could rack up in African-American communities from Baltimore to Prince George's County. That, combined with support from the Democratic powerhouse EMILY's List, which backs and funds female Democratic candidates, make her a formidable challenger.

Meanwhile, in Nevada, Reid has been working to clear the Democratic field for a Hispanic up-and-comer, former Attorney General Catherine Cortez Masto, as his chosen successor. The Democratic Senatorial Campaign Committee is reportedly already rallying behind her campaign, even though Rep. Dina Titus has indicated she's very interested in running as well. It's a no-brainer of a move, given how important the state's growing Hispanic vote has become. But it also underscores how important it is to run a familiar face to help turn out and rally Hispanic voters to the polls next November.

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Consider: When President Obama was elected in 2008, the Pew Research Center found that 44 percent of whites defined themselves more closely with Democrats, while 42 percent did so with Republicans. In 2014, that two-point deficit for Republicans has transformed into a nine-point advantage. According to Pew, 49 percent of whites now consider themselves Republicans, while just 40 percent view themselves as Democrats.

Yet among minorities, the Democratic advantage has mostly held or increased—even from the high-water mark of 2008 for Democrats. Pew found 81 percent of blacks identified as Democrats in 2008; that proportion is now 80 percent. Democrats have lost some support from Hispanics since Obama's landslide in 2008, but it's at higher levels than before Obama's presidency. In 2014, 56 percent of Latinos identified as Democrats—a larger share than when Democrats swept Congress in 2006 (51 percent). And the fast-growing bloc of Asian-American voters now consider themselves more Democratic than when Obama first took office—in 2008, 57 percent identified with the Democrats, while 65 percent now do. To get these voters to show up, Democrats need to recruit candidates who reflect their newfound diversity.

One of the paradoxes of today's Democratic Party is that, despite the increasing importance of a diversified voting coalition, the party is drastically underrepresented by talented nonwhite politicians in its congressional, gubernatorial, and statewide ranks. The great irony of Obama's presidency is that by playing to his progressive base so much, Obama oversaw the collapse of his party at the local level—and it's depriving Democrats of compelling, viable presidential recruits who reflect the changed nature of the party for 2016 and beyond.

Into that void enters Hillary Clinton. By running against Obama in 2008, she knows firsthand how powerful the appeal of personal identity is. As dramatic as the nomination fight was, the results strongly correlated with the demographic makeup of the individual states. This time, she's planning to take a page from his playbook in emphasizing her historic position as the first female major-party nominee, if she wins the Democratic nomination. That alone is enough to dissuade other qualified challengers from taking her on.

But while nominating a diverse slate of candidates is a laudable goal, there's great risk when a party becomes obsessed with identity over issues. It fuels racial polarization, where one's party label or positions on issues becomes synonymous with race or ethnicity. There's less coherent connection among their constituents' interests—beyond gender or the color of one's skin. If Clinton runs a biography-focused campaign, it will require her to be more open and authentic—traits she has never demonstrated in her long career in public life.

For all the GOP's recent internal struggles, the dividing lines within the party have primarily been over policy: tea-partiers against the establishment, Chamber of Commerce rank-and-file versus social conservatives, hawks against Paulites. Among Democrats, the dividing lines are much more personal. If Clinton wins a third straight Democratic presidential term, it will reaffirm the power of identity in American politics. But if she loses, Democrats will find themselves in a messy identity crisis, without many leaders left to turn to.

This article is from the archive of our partner National Journal.