I don’t trust anyone who tells me they already know the makeup of the midterm electorate. We can’t possibly know who will vote in the fall, let alone how they will cast their ballots.
If I were going to focus on a handful of variables to understand how the cycle is unfolding, I’d certainly pay close attention to partisanship. But instead of focusing primarily on the percentage of Republicans and Democrats among voters, I’d pay more attention to the attitudes (and then the behavior) of self-identified independents.
I looked at recent national exit polls going back to the 2000 presidential race and found that the electorate’s partisan makeup doesn’t always explain an election’s outcome.
Sure, there were many more Democrats than Republicans in the 2008 (+7 points) and 2012 (+6 points) exit poll samples, when Barack Obama won the White House and was re-elected comfortably. But the 2006 exits showed Democrats making up only 38 percent of the electorate — to the GOP’s 36 percent — while riding a 31-seat wave to take back control of the House.
And four years later, in 2010, exit polls showed Republicans and Democrats each making up 36 percent of voters at the same time the GOP was netting 63 House seats in one of the biggest electoral waves in history.
In 2000 and 2016, both presidential election years, there were more self-identified Democrats than self-identified Republicans in the exit polls (by 4 points in 2000 and 3 points in 2016). But both times, the GOP nominee won the White House while losing the popular vote.
Watch: What You Need to Know About Voter Registration and Turnout This Midterm Season
Obviously, if Democrats constitute a much larger percentage of the November electorate than Republicans — 6 or 7 points, for example — that would be great news for House Democratic leader Nancy Pelosi. But how independent voters behave could well be the more useful indicator to watch.
One reason is that the percentage of self-identified independents has been inching up recently. In the 2000 and 2004 presidential contests and the 2006 midterms, independents constituted 26 percent of the electorate. But in 2012, they were 29 percent, in the 2014 midterms 28 percent, and in the 2016 presidential election 31 percent.
Obviously, those numbers change, depending in part on the appeal of the presidential nominees and the image of the parties. Some of the 2016 independents could well have been Republicans and Democrats who didn’t like the two presidential nominees, both of whom had unusually high negatives.
But the more important reason to pay attention to independents is that they often reflect the direction and magnitude of partisan changes.
The two big wave elections of the last 20 years were both driven by independents, who voted Democratic by a margin of 18 points in 2006 (57 percent to 39 percent), Republican by an equally large margin in 2010 (59 percent to 41 percent). During Obama’s second midterm, in 2014, independents also went Republican by a substantial margin (54 percent to 42 percent).
In 2016 and 2000, independents voted narrowly for Donald Trump (by 4 points, 46 percent to 42 percent) and for George W. Bush (by 2 points, 48 percent to 46 percent). Given how close those two contests were, it probably isn’t a stretch to say that the two Republican nominees might not have won without their pluralities among self-identified independents.
The 2004 election was a bit of an outlier, I suppose. The presidential election was very close, and the electorate (according to the exit poll) had equal percentages of Democrats and Republicans. Democrat John Kerry won 49 percent of independent voters to incumbent Bush’s 48 percent. And yet, Bush won re-election narrowly, by just over 2 points.
Still, the competitiveness of the overall race and the closeness of the vote among independents does seem to confirm the usefulness of looking at how these voters perform to understand the kind of election we will have.
Watch the polls
Recent polling suggests the GOP has reason for concern about independent voters in the fall. An April 8-11 NBC News/Wall Street Journal poll, for example, found independents currently preferring Democratic control of Congress by 11 points, 38 percent to 27 percent. That’s a big margin.
A May 2-5 CNN/SSRS survey found independents preferred Democratic nominees for Congress over Republicans by a much closer 3-point margin, 43 percent to 40 percent. But since the 2016 exit poll showed Trump carrying this key group by 4 points, a Democratic advantage of 3 points would constitute a 7-point swing toward the Democrats.
Finally, Quinnipiac University’s April 6-9 national survey offers the strangest numbers. It found Democrats with a 3-point advantage on the generic ballot among all voters but Republicans with a 2-point advantage among independents, 41 percent to 39 percent. The idea that independents are more inclined toward the GOP than the overall electorate seems difficult to accept.
The attitudes of independent voters toward the president and control of Congress should provide a window into the midterms. Keep watching those numbers, especially when they come from national media polls.