Why the House still looks good for Democrats – and the Senate does not

If the mid-term elections were held today, when I'm typing those words, the results would probably not be what you expect. The Democratic Party would probably take the House back, reconquering the 23 seats it needed to hold the majority – and probably more. (Five digits out of thirty, they will win 30 seats from that moment.)

In the Senate, where Democrats only have to win two seats to take the majority? Chances are good they will not be. In fact, according to current averages of RealClearPolitics polls in contested races, the most likely outcome at the current time is that the Senate, after November 6, will be exactly like before Nov. 6: 51 to 49 in favor Republicans.

How is it possible? How could Democrats benefit from a big wave on one side of Capitol Hill but not on the other? For several reasons.

The first is that the package has always been heavily stacked against the Democrats, as we noted at our first consideration of this issue in December. There are 35 seats on the ballot next month. Twenty-six of these seats are currently held by Democrats or the two independent senators who sit in the caucus with the Democrats. In other words, the Democratic Party must defend 24 seats – and the Republicans must defend only nine.

In addition, the nature of senators' terms of office – six years in duration – means that senators must be re-elected at a different type of election than their election. If you are elected in a presidential election year, when the electorate tends to be more favorable to the Democrats, you can represent yourself in mid-term, when the field is more difficult. Most of these 24 Democrats were last elected in 2012, when Barack Obama's candidacy was re-elected. Next month's electorate will be different.

But the question is not why Democrats have problems in general, that's why worst now than in recent months.

Here is the average of polls during tight races in the Senate in recent months.

(Philip Bump / The Washington Post)

It's a bit like a plate of spaghetti, so let's separate them by party.

First, here are the seats occupied by Democrats who are currently in an average voting margin of 10 percentage points.

Note that the other very dangerous race for Democrats, Missouri, has been relatively stable. Montana, another state of Trump, has slightly worsened. Some shopping – Florida, Connecticut and Minnesota's special election to replace former Senator Al Franken – have improved.

There are three main takeaways, though. Firstly, there are a lot of Democratic races in this election. Secondly, the way polls have evolved is a little mixed. Third: the party takes place in two competitions.

Now, compare that with the Republicans.

Four seats in this polling interval. Conduit in two; tie in one (Nevada). But all four have evolved considerably to the Republican in recent weeks.

So, why change uniformly for Republicans, but not Democrats? Perhaps part of it is made up of an energetic Republican electorate after Brett M. Kavanaugh's hearings, although you expect it to show up in colder states such as Montana and Missouri. . It can also be a statistical stroke of luck, due to the small number of four races and the average based on a few polls in each.

But the point is simple. If the elections were held at the same minute and the electoral averages were perfect predictors of the results, the Democrats would lose two seats and the Republicans.

It's the Senate. On the side of the House, in the meantime, the best overall indicator of the situation is the generic ballot, this question asked in the polls, in which respondents are asked whether they prefer the Democratic or Republican candidate in their district. According to the average RealClearPolitics, this measure is only progressing.

Moreover, it is the Democrats with the structural advantage in home runs. A crowd of Republicans, seeing where this year's elections were in the trends, announced their retirement, leaving the GOP with no seniority advantage in races where a Republican holds siege.

Cook's political report estimates that Democrats should win 15 Republican-held seats, including seven without seats. An additional 29 seats (six open) are considered too close to be called. Do not forget that Democrats only need 23 seats out of 44 to win the majority.

The outstanding question of the election is this one, from Cook's Dave Wasserman.