While most political observers have been focused on the size of Mitt Romney’s bounce from last week’s debate, something else has been happening at the state level — Democratic Senate candidates have begun to break away from their Republican opponents. In Virginia, after a year-long period of stability, Democrat Tim Kaine has finally begun to break away from Republican George Allen. In the most recent Rasmussen poll, he leads 52 percent to Allen’s 47 percent, which matches his overall favorability with Virginia voters.

Likewise, in Massachusetts, Elizabeth Warren has built a solid lead over Scott Brown, in a race that was tied for most of the year. On average, according to Real Clear Politics, she leads by 3.5 percentage points. The most recent poll gives her a five-point lead over Brown among registered voters, with a 50 percent favorability rating. Earlier polls showed Warren building her support with Obama voters, and that is ongoing — she’s a short step away from winning 90 percent of Democratic voters in Massachusetts.

The polling in states such as Wisconsin, Ohio and Florida is less recent, but it shows a similar trend — Tammy Baldwin has built a 5-point lead over former Wisconsin governor Tommy Thompson, Sherrod Brown has maintained his advantage over Josh Mandel in Ohio, and Bill Nelson is still leading Connie Mack in Florida. And, thanks to the huge missteps of Todd Akin, the unpopular Claire McCaskill has found a path to reelection. If there’s a wild card, it’s in Arizona, where Democrat Richard Carmona has pulled within striking distance of Republican Jeff Flake. A GOP loss in Arizona would leave Democrats with a stronger position in the Senate than they currently hold.

It almost goes without saying that this is immensely significant for the next presidential administration. If President Obama wins reelection, a larger majority in the Senate — and a smaller Republican majority in the House — will give him a little more space to manuever, even if Senate Democrats still have to deal with procedural hurdles like the filibuster. It’s not guaranteed, but Democrats will probably get a better deal in the upcoming fiscal negotiations if they cut into the GOP’s advantage on the congressional level.

If a President Mitt Romney has to deal with a larger Democratic Senate majority, then there’s a chance that we’ll see a repeat of the early 2000s, when George W. Bush worked with congressional leaders to pass conservative bills that were somewhat acceptable to Democratic lawmakers. This, of course, would be a disaster for the conservative movement. After four years of working to kick Barack Obama out of office, they would be saddled with a technocratic Republican president who — because of the circumstances — is amenable to working with Democrats.

Of course, it should be said that if Democrats can’t build their majority — or if Republicans take back the Senate — a President Romney would move forward with the right-wing promises of his campaign. Circumstances exert considerable force on Romney’s political positions, and a world where Republicans control Congress is one where his best option is just to play along.

Jamelle Bouie is a staff writer at The American Prospect and writes a blog there.