The week after Labor Day traditionally marks the start of the midterm election season. The 2018 midterms, like most midterm elections, will be a referendum on the President. But, the current occupant of that office, Donald Trump, cuts an especially large figure in this year’s election season.
Mr. Trump faces allegations that he was complicit in a scheme to pay off a porn star and a former Playboy model in advance of the 2016 election; a special counsel investigation into possible coordination between his campaign and Russia; and an energized Democratic base. But, the economy, traditionally the most important measure of a President’s performance remains quite good and most rank and file Republicans continue to support him, despite the misgivings of his party’s moderates and intellectual conservatives.
History is on Democrats’ Side
An incumbent President’s party almost always loses seats during the mid-term election, and that seems almost certain to be the case this time. The question is, how many. Because fewer Republican seats are up for grabs in the Senate, Republicans are all but certain to maintain control of the Congress’ upper chamber. But, in the House, the Democrats stand a real chance of gaining control.
The Democrats need a net gain of 24 seats to control the House and on average, the opposition party gains 33 seats in a President’s first mid-term. Judging by historical trends alone, Democrat control of the House seems likely.
In special elections so far, that seems to be bearing itself out. Democrats outperformed their predicted margins in every special election. If the trend continues, it bodes poorly for Republicans.
Election forecasting website Five Thirty Eight gives Democrats 4 in 5 odds (80.2%) of gaining control of the House at this point. Five Thirty Eight’s midterm election model predicted a gain of at least 17 seats and as many as 59.
But, that doesn’t mean Republicans are certain to lose the House, there is a 1 in 5 chance they maintain it. Prediction models are about probability, not certainty — a fact that too many failed to consider when prediction models gave Hillary Clinton the advantage against Donald Trump. Nevertheless, median prediction in Five Thirty Eight’s model leaves Democrats with a 25 seat majority.
Energy and Implications
The defining question will be relative energy among the party’s bases. In special elections, the Democrats improved performance was mostly a function of their greater willingness to turn out to the polls. While Republicans still largely support President Trump, they are less enthusiastic about coming out to the polls to show it. If this enthusiasm gap is continued, a Democrat take over of the House is all but certain.
This will present a particular challenge for President Trump and Republicans heading into the 2020 election. With control of the House, Democrats will be in a position to initiate impeachment proceeding against the President. And in the Senate, the situation will be reversed, with more Republican seats up for re-election than Democrat. By 2020, Democrats will stand a chance of gaining control of both houses of Congress and the White House.
But, there’s a risk of Democrats overplaying their hand, as Republicans learned after they attempted to impeach President Clinton in the midst of the Monica Lewinsky scandal. Depending on what Special Counsel Robert Mueller finds, the public may judge the impeachment case against Mr. Trump to be weak. And if Nancy Pelosi, the Democrats unpopular House leader once again assumes the speakership, control of the House may prove a liability. But, whatever the case, Republicans have the odds stacked against them in the 2018 midterms and beyond.