The consensus of the polls and models is that the GOP is a clear favorite to win majority control of the Senate and pick up several seats in the House in today's midterm election. It's possible, if not exactly likely, that the polls are wrong, systematically biased against Democrats, who could still pull off a victory—or at least a less glaring defeat.

Yet either way, there's one thing we can be sure of today: No matter who wins, Barack Obama loses.

If Republicans win big, it will have been after running a tireless campaign against the president. The GOP's first line of attack against virtually all of its opponents this cycle has been to play up connections to the White House. President Obama's unpopularity, especially with swing voters in contested elections, has been the Republican party's most potent weapon by far.

President Obama is not on the ballot, but his unpopularity has given the GOP a huge boost and dragged his own party down. When a reporter from Bloomberg Politics asked a Republican strategist who the GOP's best surrogate was, the strategist responded—not entirely jokingly—that it was President Obama. Washington Post political reporter Chris Cillizza talked to more than a dozen Democratic campaign strategists and found not only "widespread pessimism" about the party's chances, but agreement on the biggest factor: "The one factor that virtually every person I talked to cited as the biggest reason for the party's predicament was President Obama." This is not just a Republican talking point. It's what Democrats working on campaigns are saying.

A Republican sweep will vindicate the party's all-in anti-Obama strategy. But if Democrats perform better than expected, it still won't be a success for the president.

That's because Democrats in close races have spent much of this campaign attempting to distance themselves from Obama. Little more than a third of Democrats have expressed clear support for Obamacare, and several, including Kentucky Democratic Senate candidate Alison Grimes, have refused to even say who they voted for. In Colorado, Democratic Senator Mark Udall has tried to portray himself as oppositional to the White House. "Let me tell you, the White House when they look down the front lawn the last person they want to see coming is me," he said in September. In Alaska, Democratic Sen. Mark Begich declared himself a "a thorn in his [posterior]." A recent rally for Sen. Mary Landrieu (D-La.) feature a parade of speakers attempting to "distance Landrieu from President Barack Obama and instead associate her with Clinton," according to The Huffington Post.

This has been the defining aspect of the Democrats' strategy in close races: Avoid looking close to Obama, even if doing so looks ridiculous. Better that than an association with the president.

The White House has, not surprisingly, been slow to accept the reality of the president's declining popularity, with loyalists insisting that Obama, who has largely stuck to fundraisers, could have helped more on the campaign. Democrats have not exactly appreciated the White House's efforts. "The ineptitude of the White House political operation has sunk from annoying to embarrassing," an anonymous Democratic aide told National Journal's Josh Kraushaar last month.

Obama himself has attempted to counter efforts by Democrats to separate themselves from him. "Make no mistake, these policies are on the ballot, every single one of them," he said last month. "These are all folks who vote with me; they have supported my agenda in Congress," he said of Democratic candidates running away from his record.

Indeed, they have. And that's why it's important to understand is that, no matter which way the election goes, this isn't just a generalized rejection of Obama, although favorable impressions of the president recently hit a record low. It's a rejection of Obama's policies. The public still opposes Obamacare. And clear majorities disapprove of the president's handling of both the economy and foreign policy.

On average, according to RealClearPolitics, just 41.8 percent of the public approves of the job the president is doing overall, while 53.4 percent disapproves. Every poll in the average shows disapproval at 50 percent or higher. The Obama era is coming to a close, and the public has rendered a negative verdict.

That has implications for the next two years, as well as for the 2016 presidential race.

Part of what it means is that if underdog Democrats overperform, they won't be able to continue to provide much cover for President Obama. The Democratic nominee, meanwhile, won't be able to simply promise a third Obama term. Democrats will have to separate themselves from the Obama legacy.

Thanks to years of all-out opposition, Republicans won't have that problem. But the anti-Obama barrage has come at the cost of a well-developed GOP agenda, meaning that Republicans will have little in the way of a clear mandate should they win. The 2016 nominee will need to do more than run against the last eight years.

Both parties, in other words, are due for resets, and this election offers multiple opportunities for new beginnings on both sides of the aisle. But regardless of what happens, it's over for Obama.