Louisiana’s Senate Runoff Probably Isn’t Going To Make Democrats Feel Better

The 2016 election season isn’t quite over yet.¹ On Saturday, Louisiana will hold runoff elections for the U.S. House and Senate. The marquee matchup is the Senate runoff between Republican John Neely Kennedy, the state treasurer, and Democrat Foster Campbell, a member of the Louisiana Public Service Commission. It’s Kennedy’s third run for Senate,² and it’s the Democrats’ last chance to narrow the GOP majority in the Senate — if Campbell wins, Republicans will have a 51-to-49 seat advantage — and derail Donald Trump’s agenda as much as they can. A look at several indicators, however, suggests that the third time will be the charm for Kennedy.

Since the first round of voting in Louisiana’s Senate race on Nov. 8 (the state holds an all-parties primary, with the top two finishers advancing to a runoff if no candidate receives a majority of the vote), Kennedy has led in every poll.

Kennedy leads Campbell 55 percent to 37 percent, according to an average of four surveys conducted mostly or completely since Nov. 8.³ None of the polls has the race closer than 14 percentage points, and all show Kennedy earning a majority of the vote. Kennedy also has a large lead in favorability ratings over Campbell, according to the Emerson College and Southern Media and Opinion Research surveys.

The polling is largely consistent with results from the first round of voting, when Republican Senate candidates crushed Democratic candidates. The nine Republicans in the primary together received 61 percent of the vote, compared with the 36 percent earned by the seven Democratic candidates. In that first round, Kennedy placed first, beating Campbell, who was in second place, 25 percent to 17 percent.

Although Campbell could make up the deficit, recent history suggests that’s unlikely to happen. In the past 30 years, there have been four Louisiana Senate elections in which a runoff was necessary.⁴ Four is obviously a small sample, so let’s not read too much into past results. Still, the runoff results have matched the first-round results somewhat closely. The margin in the first round⁵ (the cumulative Democratic vote minus the cumulative Republican vote) and the margin in the runoff⁶ were within 12 percentage points of each other every time. (In two of those races, the party with the most votes in the first round was not the party that won the second round. But the first-round results in those races were far closer than the first round was in 2016.)

Keep in mind, too, that three of the four runoffs in the table above occurred at least 14 years ago. In the only recent runoff, Republicans won both the first and second round by 12 percentage points (i.e., there was no difference in the margin). As polarization increases and the party affiliation of politicians becomes paramount for voters, one would expect less change between voting results in the first round and the runoff, even if the candidates are different.

Indeed, rising polarization has led to an increasingly strong relationship between Senate and presidential results over the past decade; this year, all states with a Senate election backed the same party in that race and the presidency. In Louisiana, Donald Trump beat Hillary Clinton by 20 percentage points. That is very close to the margin that polls suggest for the runoff. The last time a Democrat won a Senate race in Louisiana was 2008, when there was a much weaker relationship between Senate and presidential results.

The increasing power of partisanship has had a big impact on the region. None of the states in the Deep South — Alabama, Georgia, Louisiana, Mississippi and South Carolina — has a Democratic senator. (The last of these, Mary Landrieu of Louisiana, lost a re-election bid in 2014.) And in the U.S. House, there aren’t any white Democratic representatives from the Deep South. That’s because voting has become highly polarized by race. Whites vote almost exclusively for Republicans, while non-white voters almost exclusively choose Democrats. And because whites outnumber non-whites, Republicans typically cruise to victory. In Louisiana, whites made up 67 percent of voters on Nov. 8. In a neutral year (one in which Democratic and Republican congressional candidates get about the same vote share nationally), Republicans would be expected to win a statewide race in Louisiana by about 20 to 25 percentage points, based on racial voting patterns.

Kennedy is a heavy favorite to win the Senate runoff no matter how you look at it. Campbell’s best hope may be for the racial makeup of the runoff electorate to somehow differ greatly from the first round’s or for Kennedy to make a tremendous gaffe in the closing days of the race. Neither of which seems likely.

So the Republicans will probably control 52 Senate seats come January. Kennedy is unlikely to be that far to the right. He’s a former Democrat, and his past public policy statements put him closer to the more moderate wing of the GOP. An analysis by my colleague Nate Silver found him to be far more likely than Louisiana’s other senator (Republican Bill Cassidy) to defy Trump in the upcoming Congress.

One last implication from Saturday’s runoff to keep in mind: A Kennedy victory would make it much harder for Democrats to take over the Senate in 2018. The 2018 map tilts heavily in the Republicans’ favor — more seats currently held by Democrats will be up for election. And even if Democrats hold on to all their seats, they have only two⁷ realistic pickup opportunities. (At least, that’s how it looks at the moment.) With Vice President-elect Mike Pence casting the tie-breaking vote, a two-seat pickup would still leave Republicans in control of the chamber. But if Campbell were to win on Saturday and Democrats went on to take control of two additional seats in 2018 (without losing any they already hold), they would be in the majority. Kennedy will probably emerge victorious, though, and that means Trump will likely have a Senate majority for his entire first term in office.