• By
• Siobhan Hughes

Polling has consistently shown this year that the groups most enthusiastic about voting skew Republican—men over age 50, tea-party supporters and seniors among them. It’s one of the signs, commentators have often said, that Tuesday night is going to be a good one for the GOP.

But here’s a caution: Those same groups were also at the top of the enthusiasm charts in 2012—a year when Republicans lost the presidential race, along with seats in the House and the Senate.

Voter enthusiasm, in fact, may not be the most reliable indicator of who actually turns out to cast ballots. Some pollsters are rethinking their longstanding reliance on measures of enthusiasm as they try to determine the shape of the electorate.

The main issue: Many people who don’t follow the campaign with high interest—or who don’t rate themselves as highly enthusiastic about voting—actually cast ballots, suggesting that an “enthusiasm gap” that materializes in many elections is overstated as a factor.

That has become an important thread of hope for Democrats this year as election-eve surveys show many of the party’s Senate candidates trailing or in tight races. This year, as in 2012, many of the less-enthused people are younger voters or Hispanics, groups that tend to favor Democrats.

In 2012, Wall Street Journal/NBC News polling and many other surveys found that Hispanics and people age 18-34 were significantly less interested in the election than people of other racial or age groups. But when the votes were counted, it turned out that these two groups grew as a share of the electorate compared to 2008.

Latinos in the last presidential election accounted for 10% of voters, up from 9% in 2008, exit polls showed. People age 18-29 accounted for 19% of the electorate, up from 18% in 2008. That was important for Democrats, because the two groups favored President Barack Obama by large margins, helping deliver him a second term.

Once again this year, younger voters and Hispanics say they are less tuned in to the campaign than are many other groups. Journal/NBC polling in October, for example, found 29% of voters age 18-34 rating themselves as highly interested in the election, compared with 43% at the end of the 2010 campaign.

The question: Will they vote, nonetheless?

Some pollsters say that you can’t find the answer merely by looking at how these voters rate their enthusiasm. First, some voters decide early which candidate to back and then largely tune out the unfolding narrative of the campaign.

Second, both parties have fortified their voter-turnout operations, meaning that lower-interest voters are more likely to be pushed by the campaigns to cast ballots.

“If your people are enthusiastic, it’s important. But enthusiasm on its own doesn’t always tell whether someone is voting for you or not,” said Joel Benenson, the founder of Benenson Strategy Group and the chief pollster and a senior strategist for Mr. Obama.

Thinking back to his work in 2008, Mr. Benenson said that among people who said their likelihood of voting was only 50-50 –well below the threshold for being counted as highly interested or enthusiastic—about two-thirds actually cast ballots.

Or, as Neil Newhouse, Mitt Romney‘s pollster in 2012, recently told the Washington Post: “Sadly, I learned that unenthusiastic votes count just as much as enthusiastic ones.”

Republican pollster Bill McInturff, Mr. Newhouse’s business partner, thinks many Democratic groups are likely to stay home on Tuesday. But he leaves room for the party’s turnout efforts to prove effective in countering the many factors this year that favor the GOP.

For Democrats, there may be “a wall that can be built high enough to withstand the tide,” said Mr. McInturff, who directs the Journal/NBC poll with Democrat Fred Yang.

Republicans this year are amplifying their get-out-the-vote efforts, just as Democrats are. That makes this year a laboratory to investigate the question: How much does voter mobilization matter compared with voter enthusiasm?

“That’s what’s being field-tested in this election,” said Michael McDonald, a political scientist at the University of Florida who runs the U.S. Elections Project, which is tracking the elections.

Either way, some pollsters say that they have learned not to overstate the importance of enthusiasm ratings.

“You can be unenthusiastic and still vote,” said Ann Selzer, the president of polling firm Selzer & Co. “Your vote counts the same.”

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Latest midterm polls | Senate map, contest | WSJ/NBC Poll

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