Election Day is less than 24 hours away and the probability of Republicans gaining control of the U.S. Senate is high. FiveThirtyEight, the Upshot, HuffPost Pollster, the Princeton Election Consortium—all of them say the chances of a Republican takeover are somewhere between 65 and 75 percent. That’s a strong consensus.

What would this mean for the next two years? Republicans say that, without Harry Reid and Senate Democrats controlling the agenda, they will be able to work with their House counterparts to pass legislation. President Obama is likely to veto most of it, they acknowledge, but that will merely play into the GOP’s hands—allowing them to set up the 2016 elections as a clear choice between a party that gets things done and a party that does not. “No question about that, he'll veto some [bills],” Mitt Romney, the former GOP presidential nominee, said on Fox News Sunday, “but I think at that point, we'll find out who really is the party of no.”

It’s true that a Congress with Republicans in charge of both chambers is likely to pass more bills than a Congress with divided control would. But would Republicans actually benefit politically? That’s not clear at all.

For one thing, the laws they want to pass might not be that popular—or at least electorally helpful. During that Fox News interview, Romney mentioned two pieces of legislation he thought a GOP Senate would pass: immigration reform and a bill to modify Obamacare’s requirement that employers provide health insurance to full-time employees. But the politics of immigration reform are tricky for both sides: An immigration bill sufficiently tough to get past the Tea Party in the House (and maybe the Senate too) is likely to alienate Latinos, at a time when Republicans desperately need to start appealing to them. As for Obamacare, the kinds of changes to the employer mandate that Republicans are contemplating could have some signficant (and negative) effects on the labor market. Obama would not have a hard time defending a veto.

Of course, the point of passing legislation isn’t simply to change policy. It’s also to change the GOP’s image, from a party that is standing in the way of progress to a party that is trying to produce it. But that’s going to be difficult as long as the GOP keeps trying to block Obama appointments for the executive branch and judiciary. This has been a running theme of the Obama presidency: He puts forward nominees and Republicans use what leverage they have to stop those nominees from taking office. Obama has mostly succeeded in getting his people in place eventually, thanks in no small part to Reid. But things are going to change if Republicans are in change and Mitch McConnell is the majority leader. As TPM’s Sahil Kapur reported recently, conservative activists and strategists are counting on McConnell and Charles Grassley, who would be chairman of the judiciary committee, to block a wide array of Obama nominations simply by refusing to bring them to a vote.