If The Democrats Hold The Senate

Ramesh imagines the GOP reaction:

Many conservatives … would argue that the party establishment had led them to ruin. The establishment largely got its way in the 2012 presidential primaries, and then got its way again in running an agenda-less general-election campaign. This time, Exhibit A for these conservatives would be the North Carolina Senate race, where the establishment candidate — Thom Tillis, the speaker of the state House — has persistently run a little behind his Democratic opponent. (Actually, that might be Exhibit B if Senate Minority Leader Mitch McConnell manages to lose in Kentucky.)

Conversely, a lot Republican officeholders might conclude that the Democratic attacks on them as uninterested in compromise and hostile to women had succeeded, and that they should accordingly move leftward.

Should the Democrats pull off an upset, Nate Cohn will look “to the challenges of modern polling as a big reason for the surprise”:

In 2010, the polls underestimated the Democrats in every competitive Senate race by an average of 3.1 percentage points, based on data from The Huffington Post’s Pollster model. In 2012, pre-election polls underestimated President Obama in nine of the 10 battleground states by an average of 2 percentage points.

A couple of elections in which polls tilt slightly Republican aren’t enough to prove anything. The polls have erred before, only to prove fine over the longer term. But the reasons to think that today’s polls underestimate Democrats are not based on just the last few years of results. They are also based on a fairly diverse set of methodological arguments, supported by extensive research, suggesting that many of today’s polls struggle to reach Democratic-leaning groups.

But liberals shouldn’t get too excited:

The biggest reason to be skeptical that the Democrats will fare better than the polls predict is the context: The Republicans probably have a large enough advantage to withstand another round of modest polling errors. Even if there is another three- or four-point error in Colorado, for instance, the result would be a dead heat in a race that on its own is not at all sufficient for Democrats to hold the Senate. And the Republicans could just as easily counter the effect of any polling error by winning undecided voters, who tend to disapprove of Mr. Obama’s performance — along with their incumbent Democratic senator, Mark Udall.

Even with the problems that polls have, the Republicans’ advantage is clear enough to make them favorites to win the Senate.