Noted political prognosticator/statistician concludes Republicans are “slight favorites” to regain control of Senate this fall

 

By Dave Andrusko

Nate Silver

Nate Silver

Predictions in late March, even from political prognosticators with the track record of Nate Silver, are food for thought but hardly definitive. Yet because Silver absolutely nailed the results of the 2012 presidential election, correctly predicting the electoral outcomes in all 50 states, it’s like the old commercial: “When EF Hutton talks, people listen!”

So there’s been a mini-avalanche of stories since Silver wrote

“We think the Republicans are now slight favorites to win at least six seats and capture the [Senate]. The Democrats’ position has deteriorated somewhat since last summer, with President Obama’s approval ratings down to 42 or 43 percent from an average of about 45 percent before. Furthermore, as compared with 2010 or 2012, the GOP has done a better job of recruiting credible candidates, with some exceptions.”

(As we’ll see below, emphasis on the words “slight favorites.”)

Most of the stories are obvious: Will Republicans and Democrats exchange places on Silver, with GOPers now loving what he writes and Democrats now hating it. A more interesting tack is to examine why Silver’s forecast has moved “a half-step further” from what he wrote in July—that control of the United States Senate was a “toss-up.” (Silver tells us that even back then his view differed from the “conventional wisdom at the time, which characterized the Democrats as vulnerable but more likely than not to retain the chamber.”)

I will not go into great detail, because I’m guessing most people, like me, would likely get lost. Here are a couple of factors which suggest the wind is blowing at the Republicans’ back.

The “generic congressional ballot” (without any names given, people are asked if they would vote for a Democrat or a Republican) is favorable, although that is not obvious at first blush and takes some digging.

Second, Silver writes,

“Democrats’ other problem is one of basic constitutional mathematics. Senators are elected in six-year cycles, so the seats in play this year were last contested in 2008, an extraordinarily strong year for Democrats. Even a strictly neutral political environment, or one that slightly favored Democrats, would produce a drop-off relative to that baseline. And Democrats’ losses will grow this year if voters go from modestly favoring Republicans to strongly favoring them.”

Obviously, the same dynamic can work in a different election cycle against Republicans—but not 2014.

What about ObamaCare, a disaster if ever there was one for Democrats. Silver tells us he prefers

“to look at aggregate measures of the national environment, like the generic ballot and Obama’s approval ratings, instead of piecemeal ones such as voters’ views of Obamacare. Certainly the unpopularity of the Affordable Care Act — and its clumsy roll-out late last year — contributes to Democrats’ problems. But it’s hard to tell where Obamacare’s unpopularity ends and President Obama’s overall unpopularity begins”

There are a flock of other components Silver factors into his forecasts, including “candidate quality”; “state partisanship”; “incumbency” (most incumbents win re-election but “We can spot the potential exceptions by looking at an incumbent’s approval or favorability ratings”); and the like.

Silver then goes through the races state by state and ends with this:

“There are 10 races that each party has at least a 25 percent chance of winning, according to our ratings. If Republicans were to win all of them, they would gain a net of 11 seats from Democrats, which would give them a 56-44 majority in the new Senate. If Democrats were to sweep, they would lose a net of just one seat and hold a 54-46 majority.

“So our forecast might be thought of as a Republican gain of six seats — plus or minus five. The balance has shifted slightly toward the GOP. But it wouldn’t take much for it to revert to the Democrats, nor for this year to develop into a Republican rout along the lines of 2010.”

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