US Congressional election: Republicans gain in the Senate, the House stays Democratic

With ten days to go before the US mid-term election the Senate and House races have diverged. The Senate has moved to a more decided Republican edge while the House and the generic preferences are unchanged.  

Voter choices in the state wide Senate elections are starting to point in their historical direction with several but not all of the races in the middle of the country tending to the GOP. The evidence of the trend in the larger and easier to poll state races may mean that some House contests are experiencing a similar shift that is uncharted due to the scarcity of polling.

The notion of a few months ago that the Democrats  would roll through the  election in a wave has been discarded since the contested Supreme Court hearing of Brett Kavanaugh and the decision is now solely centered on control of the House of Representatives. Though the odds for the Democratic takeover of the House are the same as they were a week ago, recent voter changes seem to favor the Republicans. 

Movement in voters’ preferences at this stage of the campaign is more telling than variations earlier in the season. Many people do not focus on the candidates and issues until the last two weeks before an election and choices made now are usually final. Trends that are established now, in the run up to the election, are, in close races, the choices that decide contests.

If the tentative movement seen in the Mid-West and South-West to Republican candidates does represent the first wave of that late arriving voter, the statistical confidence of a Democratic House could be overstated.

The most likely scenario, however, remains the Democrats winning control of the House and the Republicans retaining the Senate

Markets

Implications for the equity, currency and credit markets are governed by the success of the US economy in the past two years, the Federal Reserve’s rate policy and the prospect that the policies of the Trump administration would be largely untouched if the Democrats gained the House but not the Senate.

As that remains the favored outcome, and has been so for many weeks, it is priced into the currency and credit markets. For the equities it was incorporated before the October swoon. Stocks have interest rate, tariff and profit-both corporate and trading-worries enough to justify the sharp sell-off this month. The bitterness and uncertainty of the election may be adding to the unease in the equity markets but the likely outcome of the election is not. 

Democrats take the House, Republicans retain the Senate

Senate

At FiveThirtyEight, the statistical analysis site, Republican odds in the Senate were 78.7% last week, those have shifted noticeably higher to 83.2%. Democratic chances in the upper house were 21.4%, they have dropped to 16.8%. 

Interestingly, these percentage shifts have taken place even though new RealCleanPolitics (RCP) averages give the Republicans one fewer Senate seat. Last week the Republicans were projected to win three new seats, 54 with 46 for the Democrats. The current Senate is 51 Republicans and 49 Democrats.  The changes in the Senate races had North Dakota, Missouri and Florida all currently Democratic, becoming Republican. North Dakota and Missouri were won by Donald Trump by wide margins in 2016, he took Florida also but by just 1.2%.  

In the past week Florida has moved to the Democratic column, losing its slight Republican advantage as several new polls were posted. Though the GOP gained no new seats in the averages, their candidates in four states, Missouri, Arizona, Nevada, and North Dakota, enlarged their margins. Two other states in Trump country, Indiana, and Michigan saw substantial gains in the polling averages by Republican challengers, in Michigan by ten points. In two states won by Trump, Montana and Florida, the Democratic incumbent added to his lead. This movement in so-called Red State polls at RCP seconds the statistical improvement of Republican chances at FiveThirtyEight. Overall six states have moved toward the Republicans with two to the Democrats.

House

Last Friday FiveThirtyEight Politics, had the odds of a Democratic victory in the House at 84.5% that is unchanged. The House averages at RealClearPolitics (RCP) gave the Democrats a gain of 26 seats, three more than the 23 needed for a majority.  This week that addition is 25.5.  The spread of potential changes was 10-42 seats on October 19th, now it is 10-41, 32 seats were considered toss up then, it is now 31. 

The high percentage given to the Democratic House by FiveThirtyEight is somewhat deceptive. The House will turn on the victories in very few contested districts, all now considered too close to call. There will be little new polling in most House districts before November 6th.

If the Republican trend detailed in several Senate races above is genuine it has serious implications for the House as well.

Twelve of the 31 House seats listed by RCP as toss up are in states won by the Republicans in 2016. By themselves they are not enough to deny the House to the Democrats. With 205 districts listed as leaning or likely Democratic the remaining 19 seats would give the Democrats 224, six more than the 218 majority. But a trend strong enough to win in these 12 districts, or some large portion of them, would have similar effects in many other contested areas.

If the allegiance of late deciding voters in Red States in the Mid-West and South-West, traditionally Republican, says true to form, and if the movement in the several states mentioned above also indicates an intention to vote, the control of the House will be a near run thing.  The first is probably close to certain, the second is unknown.

The 23 seats that the Democrats are said to need to win control is based on the current House division of 193 Democrats and 236 Republicans.

Democrats take the House and Senate

Democratic odds in the House from FiveThirtyEight remain at 84.5% but their chances in the Senate have fallen to 16.8% this week from 21.4% last week.  Their odds of a double takeover have fallen by the differential in their Senate percentages.

RealClearPolitics agrees on the House with 205 Democratic likely seats, 199 Republican and 31 toss ups. On the Senate side the averages have given up one seat to 53 but the movement in several states to the Republican candidates, even though the poll averages have not flipped, supports the improving Republican odds of keeping control of the Senate.

Republicans keep the House and Senate

Odds here have stayed the smallest but there has been a slight uptick. FiveThirtyEight gives the Republican the same 15.4% chance of staying in control of the larger body as last week but their Senate changes have gone up to 83.2% from 78.7%. Thus their overall average is better though still below the Democratic odds for double control.

Generic vote

The spread of Democratic preference over Republican was the same this week as last 7.6%.  This difference has fallen almost two points in eight weeks. On the September 4^th it was 9.5%.  In October the gap has varied from 6.6% on October 7^th to 7.7% on the 22^nd.  The current difference does not indicate a large surge of Democratic voters.

This poll charts the stated desire for a generic Republican or Democratic candidate. There are more registered Democrats than Republicans and this poll has historically overstated the Democrats predicted vote over the actual percentages by about 7.2 percent in post war elections. In practice that means a Democratic lead in that area likely indicates an electorate nearly tied.

FXStreet US Congressional election coverage

Why the House vote is difficult to predict -  October 22, 2018

Is geography destiny? - October 19, 2018

Can the Republican economy hold off the Democrats? - October 14, 2018

 

Political map - Senate

Political map - House

Political map - generic vote