Beto O'Rourke, a Democrat, campaigning for Senate in TexasWilliam Philpott / Reuters

Few Democratic leaders in 2006 dared imagine they would capture the U.S. Senate in the midterm elections. Yet there they were on the morning of November 9, celebrating on the Capitol steps after ousting six Republican incumbents. President George W. Bush lamented, “It was a thumpin’,” and indeed it was. Many factors fueled the thumpin’—including broad grassroots opposition to the bloody Iraq quagmire—but Democrats also managed to convince voters that Bush and his congressional allies needed to be held accountable for spawning “a culture of corruption.”

Democratic midterm strategists in 2018 are seeking to repurpose that buzz phrase—fueled anew by the arrest of Representative Chris Collins for alleged insider trading, the Paul Manafort bank-fraud trial, the Michael Cohen tax-fraud investigation, and the latest fervent attempts to protect Donald Trump from the Russia probe. But even though prospects look bright for a House takeover, the current Senate map seems more daunting for Democrats than it was in 2006. A net gain of only two seats, sufficient to win the upper chamber, may be as tantalizingly elusive as a mirage.

The past two years should remind us that conventional wisdom is dead, that the deck is stacked with wild cards, that what seems politically plausible in the moment can be rendered moot by unforeseeable events. To borrow a phrase from Donald Rumsfeld, we’re living in a time of “unknown unknowns—the ones we don’t know we don’t know.” What we do know is that Democrats are suddenly competitive in House districts that Trump won by double-digit percentages. What we do know is that Democrats won a special Senate election in Alabama last December, the first blue Senate win in that red state since 1992. What we don’t know is what wild cards await us. What we don’t know is whether or what Special Counsel Robert Mueller might report between now and November, and how his findings might feed or deflate the Democrats’ corruption theme.

If we stick with only what we know, it remains conventional to believe, for instance, that Senator Ted Cruz will win reelection in red Texas—the political handicappers don’t view him as highly vulnerable—but it’s not implausible to believe, in a blue-wave year, that his challenger, Beto O’Rourke, who’s outraising Cruz in the money chase, and who was within the margin of error in a recent poll, could shock us all when the votes are tallied.

If we stick with only what we know, we’ll focus mostly on the House—which seems poised to flip because Democrats are strong in districts dominated by college-educated suburbanites. As the conservative political analyst Henry Olsen said the other day, “We’re not talking about whether or not the Democrats are going to do extremely well. We know Democrats are going to do extremely well.” By contrast, the Senate will be largely contested in the rural and small-town red states where Trump scored solid wins in 2016; Democrats have the misfortune of defending 10 Senate seats on Trump turf. And Trump is betting, not without reason, that most voters in those states will be galvanized by his pet themes: race and culture.

He knows that GOP control of the Senate is crucial not just to his agenda, but to his survival. If Democrats win the chamber, they would snuff his ongoing mission to appoint conservatives to the federal judiciary. And if Democrats win the House and move on impeachment, presumably with evidence amassed by Mueller’s team, Trump wants to ensure that the Senate won’t have the votes to convict—or the power to conduct new investigations.

So, with help from his media friends, he’s pushing the hottest button of all. On air yesterday, the Fox News host Laura Ingraham, a stalwart ally, framed the stakes for Trump voters: “The America we know and love doesn’t exist anymore. Massive demographic changes have been foisted on the American people, and they are changes that none of us ever voted for, and most of us don’t like … This is related to both illegal and legal immigration."

Ingraham was swiftly assailed for peddling white nationalism—the conservative commentator S. E. Cupp tweeted at her: “Speak for yourself, and every other last gasp of a dying gen … WE love this country’s diversity”—but, her visceral rhetoric aside, what’s arguably most noteworthy is her targeting of legal immigration. This appears to be a new front for the Trump-allied forces, as also evidenced by a pending White House plan to revoke the resident status of legal immigrants who enroll in federal-aid programs—such as food stamps and public housing—to which they are currently entitled.

Until now, they were only targeting undocumented immigrants; now they’ve expanded their ambitions. The broad theme—which they hope will resonate in the key red-state Senate contests—is that Trump and his Republican candidates are strong on keeping all immigrants at bay, and that the Democrats are weak. And the strategy might work; according to a June poll conducted by the Pew Research Center, a plurality of Republicans nationwide cite immigration as their top issue of 2018.

The Republican mood has become more churlish since 2006. Democrats scored their pivotal 51st seat when the Republican incumbent George Allen lost his Virginia race by one-half of 1 percent; his defeat was blamed on an incident when he’d singled out an apparent immigrant in his audience and said: “This fellow here, over here with the yellow shirt, macaca, or whatever his name is … Let’s give a welcome to macaca here. Welcome to America and the real world of Virginia." The word macaca is widely considered to be a racial slur against African immigrants. Allen’s target turned out to be a native-born Virginian whose parents came to America from India. It’s questionable, in many red states today, whether a Trump Republican would be similarly doomed for impugning immigrants.

Today, Trump’s strategy is to use the immigration issue to squeeze red-state Democratic senators running for reelection. It already appears to be working in Trump-friendly Indiana, where Joe Donnelly is trying to save himself. In 2012, he had the good fortune of drawing a flawed Republican opponent—Richard Mourdock, who publicly declared that any woman impregnated by a rapist was carrying “a gift from God”—but now Donnelly is being hit with advertising that depicts scary figures pouring over the border and says he has “waffled” on building a wall. Donnelly has thus hastened to insist that he’s “fine” with more funding for a wall.

Trump, who is prominently featured in that anti-Donnelly ad, won by double digits two years ago in Indiana, Missouri, Montana, North Dakota, and West Virginia. He won by single digits in Arizona, Florida, Ohio, Pennsylvania, and Wisconsin. Democratic senators are on the ballot in all 10 states. Many seem well poised to win in November—most notably, Bob Casey in Pennsylvania, Sherrod Brown in Ohio, Tammy Baldwin in Wisconsin, Jon Tester in Montana, and Joe Manchin in West Virginia—but Democrats need to save virtually all of them, including Donnelly, if they are to have any hopes of netting the necessary two seats for a Senate flip.

To pull off that minor miracle, they’ll also need to win at least two of the three targeted red seats: Tennessee (where Bob Corker is departing), Arizona (where Jeff Flake is departing), and Nevada (a blue-tilting state where the incumbent Republican, Dean Heller, is imperiled). Trump in 2016 won Tennessee by double digits; Arizona, by single digits. His hot-button immigration emphasis may be potent enough to mobilize base turnout, particularly among white seniors who vote heavily in midterms.

The Democrats’ current counterstrategy, to stoke their own turnout among young people and minorities who usually skip midterms, worked well in Alabama to derail the conservative Roy Moore, but it has yet to be tested in red states spanning the national map. Moore was fatally hampered by child-molestation accusations; this fall, with no Moores on the ballot, numerous red-state Democrats may be forced to play defense because of Trump’s culture war. The last thing they want, on Trump-friendly turf, is to play defense on immigration and diversity.

Such are the known knowns. But be prepared for the unexpected. The Democrats of 2006 took the Senate despite conventional wisdom that decreed that flipping six seats was implausible. The current wisdom is that flipping two seats is implausible. Perhaps we’ll wake up on November 7 with the urge to invoke Red Smith, the renowned sportswriter who opined, after one miracle baseball climax, that “only the utterly impossible, the inexpressibly fantastic, can ever be plausible again.”

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