Tea Leaves Still Signal Democratic Edge in Battle for House Control

With fewer than 200 days until the midterm elections, Democrats are generally thought to have a slight advantage in the fight for control of the House. That doesn’t mean they are going to prevail. The polls could be wrong, as all should understand by now, and there’s more than enough time for the national political environment to turn in favor of the Republicans. But these four indicators, for now, are consistent with a Democratic edge. Here’s what they are and what they are telling us.

One of the best measures of the national political environment is the generic congressional ballot, a poll question that asks voters whether they intend to support Democrats or Republicans in the next election.

The final generic ballot numbers typically perform well in approximating the House popular vote, even this far ahead of an election. And Democrats can reasonably hope for their lead to grow, given the tendency of the measure to break toward the party out of power.

The Democrats’ lead on the generic ballot is about 7 points, one of their weakest leads of the past year. At their peak, in December, Democrats led by 13 points, after the passage of the Republican tax cut bill.

Obviously, the larger the lead for the Democrats, the better their chances this November. But even a 7 point advantage is far from bad news for the party. In recent wave elections, the party out of power has won the House national popular vote by 6 to 8 points. So there’s no contradiction between a 7 point Democratic edge and an extremely favorable national political environment. It’s also consistent with most of the reporting on the status of specific Republican incumbents. A recent Politico article, for instance, described Republican troubles in traditionally safe districts like North Carolina’s 13th, North Carolina’s 9th, Virginia’s 2nd, Virginia’s 5th and Virginia’s 7th.

By our estimates, those are exactly the sort of districts that should be vulnerable in a Democratic +7 political environment. Similarly, the distribution of Cook Political Report House Ratings are very similar to what we would expect for a D+7 environment.

The fundamentals of this election cycle are clear: The party out of power usually dominates in midterm years when the president has an approval rating less than 50 percent. These conditions have yielded a wave election in comparable situations since 1978.

If we take the past three decades of election results, a 41 percent approval rating, President Donald Trump’s current rating, in a midterm year would suggest about an 8 point victory for the party out of power in the national House popular vote.

These fundamentals provide only a rough sense of what might happen in an election year. But in this case, they seem to line up with everything else.

In the special election in Arizona on Tuesday, the Republican, Debbie Lesko, won by just 5 points in a district that Trump won by 21 points. There were no excuses for Republicans: The candidates were typical, the turnout was typical, and the GOP fought hard for the district.

On average, Democrats have run 14 points ahead of a district’s partisanship (as measured by the last two presidential elections, compared with the national popular vote) in special elections for Republican-held districts so far this cycle. They have run more than 20 points ahead on three occasions — Kansas’ 4th, Pennsylvania’s 18th and Arizona’s 8th — and that doesn’t include Doug Jones’ victory in the Alabama Senate race.

These Democratic over-performances are a startling departure from the Obama years, when congressional election results polarized along national political lines.

Over the more than 1,000 special and general House elections in Democratic-held districts in the Obama era, there were only four elections when the Republicans ran 20 points ahead of the district’s lean in presidential elections. This cycle’s Democrats have pulled it off three times out of seven.

In a broader historical context, though, the Democratic overperformance is not quite as startling. It is still impressive, but the Democrats ran 20 points ahead of a Republican-held district’s presidential partisanship in 31 races combined in 2006 and 2008. Overall, the Democrats’ performance in 2018 special congressional elections looks a lot like their showing in open districts in 2006, and well above the average from wave elections in 1994, 2006, 2008 and 2010. On average, Democrats ran 14 points ahead of a district’s partisanship in open races in 2006 — exactly the same as their overperformance so far this cycle. The Democrats had a similar 10-point overperformance in 2008.

But 2006 is at least somewhat a cautionary tale for Democrats. Despite a big wave, they flipped only 31 districts — a tally that would put the Democrats over the top this year (they need to flip 23), but not by much.

Republicans held down their losses because their incumbents did pretty well. How well will incumbents fare in 2018? That’s a big question heading into the heart of the election year. Since 2006, the value of incumbency has diminished. Instead, congressional elections have moved closer to aligning with presidential election results.

At the beginning of the cycle, Republicans seemed to possess big structural edges: the advantages of incumbency, gerrymandering and geography. Combined, they appeared to give the party the ability to survive a wave election.

Those advantages still exist, and the Republican House majority could still survive a wave. But the GOP’s advantages are diminished. Here’s why:

— Court rulings have weakened or undone Republican gerrymanders in Pennsylvania, Virginia, North Carolina and Florida.

— An unusually large number of Republican incumbents have retired, in many cases well-established moderates with the best chance of riding out a wave election, like Dave Reichert in Washington, Frank LoBiondo in New Jersey and Ileana Ros-Lehtinen in Florida.

— Where Republicans are running for re-election, Democrats have generally succeeded in luring viable recruits backed by abundant fundraising. The strong Democratic recruitment, in effect, tends to cut against the GOP’s incumbency advantage. Put it together, and the House Republican majority doesn’t look safe in today’s national political environment. As recently as late 2017, you could credibly argue that Republicans would be solid favorites if the Democrats led on the generic ballot by 7 points. The Republicans have managed to narrow the Democratic advantage to exactly that figure.

But after so many retirements and a redrawn map in Pennsylvania, Republicans would seem to be clear underdogs if Democrats won the popular vote by 7 points.