Democrats remain clear favourites to gain control of Congress at midterms as Trump’s ratings slide again

With eight days until the November 3 US midterm elections, Democrats have a three in four chance of gaining control of the Senate, and remain overwhelming favourites to gain control of the House of Representatives in Nate Silver’s forecast model. Democrats lead Republicans by 9.5 points on the generic ballot, and Donald Trump’s net approval is -23.3. There hasn’t been much change in the forecast during October. If disruption caused by the Iran war continues until the midterm elections, with increased petrol prices and inflation, Republicans are likely to lose control of both the House and the Senate, perhaps with huge losses. With the oil price surging recently, petrol prices are likely to increase again before the midterms. Trump’s ratings In Silver’s aggregate of US national polls, Trump’s net approval is -23.3. Currently, 60.2% disapprove of his performance and 36.9% approve. Trump’s net approval had fallen to a new low of -24.3 last Wednesday before rising slightly. In an October 19–20 YouGov poll, by 66–3 respondents sympathised more with Ukraine than Russia in the Ukraine–Russia war, but by 45–16 they thought Trump sympathised more with Russia. Trump’s October 9 announcement of a diesel import deal with Russia hasn’t helped him. Trump’s net approval was -22.3 in my October 19 article. His net approval had improved to -18.7 on September 4 before falling back. Trump’s net approval is below what any past president since Harry Truman had at this point in their term, with Joe Biden the closest at -10.7. On four issues tracked by Silver, Trump’s net approval is -13.2 on immigration, -29.9 on trade, -32.6 on the economy and -46.0 on inflation. Since my October 19 article, Trump’s net approval on inflation has improved three points, but has dropped two points on immigration. Silver also has an aggregate of US support for the Iran war. Currently, 55.2% are opposed to the Iran war while 36.3% support it, for a net support of -18.9, up from -21.0 in my October 19 article. This is the highest net support since late August, and off a record low of -27.9 on October 6. When the Iran war is out of the news headlines and petrol prices are not rising, support for it increases. Midterm elections on November 3 All 435 federal House of Representatives seats and 35 of the 100 senators will be up for election at November 3 midterm elections. In 2024 elections, Republicans won the House by 220–215 over Democrats and the Senate by 53–47. Owing to Vice President JD Vance’s potential tie-breaking vote, Democrats need at least a four-seat gain to win Senate control. As I previously wrote, owing to Republican gerrymandering, Democrats need at least a four-point margin in the generic ballot to have a good chance to win the House majority. The Senate is more skewed to Republicans as every state has two senators. Democrats need a double-digit margin in the generic ballot to win the Senate on a uniform swing. In Silver’s midterm election forecast model, the generic ballot gives Democrats a 51.6–42.1 lead over Republicans, a 9.5-point margin (down slightly from 9.6 points in my October 19 article). Democrats’ lead had dropped to 7.4 points on September 4. Polls that screen for likely voters usually give Democrats larger leads than polls that ask registered voters. Democrats are more likely to vote at lower turnout elections like the midterms than Republicans, when Trump is not on the ballot. Silver’s model gives Democrats a 75% chance to win the Senate and a 95% chance to win the House, respectively 75% and 94% on October 19. Democratic chances of winning the Senate had fallen to a low of 50% on September 7, and their chances of winning the House had dropped to 81% on September 3. While uniform swing indicates that Democrats need a double-digit margin in the generic ballot to win control of the Senate, Silver’s model has Democrats as the favourites to win with a 5–6 point margin in the generic ballot. In the House, Democrats are favourites if they win by 2–3 points. Democrats lead Republicans by one to four points in polls of Kansas, Iowa, Texas, Alaska and Ohio. Trump won all these states by double-digit margins in 2024. However, Democrats only lead by two to three points in Republican-held Maine and Democratic-held Michigan. Kamala Harris won Maine by 6.9 points in 2024 and Trump only won Michigan by 1.4 points. Economic data Americans are currently paying an average of US$4.29 a gallon for regular petrol (gasoline in the US), down from US$4.36 a gallon in my October 7 article and US$4.48 on September 25. Owing to profits and taxes, the retail price of petrol will be higher than the commodity price. The commodity price of petrol had surged from a low of US$2.99 a gallon on August 27 to US$3.59 on September 23, but fell to US$3.12 last Tuesday before rising to its current US$3.18 a gallon. However, the international benchmark Brent oil has surged from US$96.16 a barrel on September 29 to US$116.72 last Friday, the highest it has been during the Iran war. There appears to be a lag between changes in oil prices and petrol prices, so petrol prices are likely to increase again before the midterms. In Silver’s models, Trump and Republicans were at a high in early September, shortly after the August 27 low point in petrol prices. After combined losses of 1.7% in the last two trading sessions, the benchmark US S&P stock market index was down 0.5% last Friday since October 16 and down 2.5% from its October 6 peak. But it was still up 9.8% from its peak in the week before the Iran war began in late February and up 15.7% from its worst point in the Iran war in late March.