The post-shutdown bounce for Democrats has disappeared, and Obamacare looks like the reason why. According to the latest Wall Street Journal/NBC Poll a plurality of Americans want Republicans to run Congress, a 10-point swing in just two months (PDF). As a result, Democrats are again confronted by the demographics that usually typify midterm elections, in which older and white voters dominate and younger and minority voters recede from their presidential election year peaks. In 2014, this generational and racial ebb could tip control of the Senate to Mitch McConnell and the GOP.

Democrats face a huge problem with Obamacare so unpopular among whites, with the President so distrusted by whites, and with both the President Obama and Majority Leader Reid facing the “six-year itch where the party that controls the White House is expected to lose congressional seats just for being in power for so long.

To be sure, the white vote alone no longer determines who wins the presidency. Lyndon Johnson was the last Democrat to win a majority of white votes and White House. Jimmy Carter, Bill Clinton and Barack Obama all made it to 1600 Pennsylvania Avenue by cobbling together a coalition of the polychromatic. But midterm elections are a different story, as white voters remain a driving force as to which party gets to run Congress.

The elections of 2010 and 2012 tell the story. In 2010, whites comprised 77 percent of the electorate and went Republican by better than three-to-two. As a result, the GOP recaptured the House. In contrast, last year whites voted Republican by the same 20-point margin but Mitt Romney still lost to the president—as minorities cast a larger proportion of ballots and blacks showed “a significant increase between the 2008 and 2012 elections in the likelihood of voting,” per the Census’ post-election survey.

That brings us to Obamacare. White voters may be feeling as if they are Obamacare’s victims more than its beneficiaries. Whites comprise 64.3 percent of the overall population, but are only 45.3 percent of America’s uninsured and have an uninsurance rate of little more than 11 percent.

Further, Obamacare is redistributive, as Jonathan Cohn of The New Republic and Tom Edsall at the New York Times acknowledge. So, enter Obama’s false promise that “If you like your health plan, you can keep it.” But instead of Obamacare simply being a wealth transfer to the lower income precincts of the president’s base—as intended and as understood—it has also shown itself to be inept and disruptive, with the middle class getting gored too.

Nationwide, Obamacare’s “net enrollment stands at about negative four million,” notes the Wall Street Journal. Likewise, the Associated Press just reported that among those who are keeping their employer- based policies, nearly half say that “their policies will be changing next year—mostly for the worse,” with rising premiums, deductibles and co-payments. More ominously for the Democrats, almost 80 percent of those surveyed blame Obamacare. Expect Republiacns to say Obamacare is a case of the many being asked to pay for the few and getting no tangible benefit in return.

As a presidential year strategy, this message proved to be a loser. Remember Romney’s “47 percent” comments? As a midterm tactic, however, it could be enough to get the job done, as it previously did in 2010.

Already, Republicans are predicted to pick up open Senate seats in Montana, South Dakota, and West Virginia, and so the GOP simply needs gains in three more states to retake the Senate, which at this juncture remains no small thing.

If the drip, drip, drip of bad news for Obamacare’s continues, Democrats may be made to pay for their attempt to legislate a major government benefit without requiring work in return for taxpayer largesse. In the end, Obamacare may give Republicans the Senate after giving them the House four years ago.