• Democrats on deep defensive in Senate

• Ohio race looks the highlight

• GOP to pay for chaotic House session

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The race for the White House may consume most attention, and dominate media coverage, but don't forget this a is a general election, with much more than the presidency on the line.

Congress control is on a knife-edge

All 435 Congressional districts are up for re-election, to determine which party controls the House of Representatives, plus 34 of the 100 seats in the US Senate. Here's what to expect.

Going in, Republicans control the former, Democrats the latter. Both by very narrow margins. This gridlock makes it very difficult for government to legislate, and has been a consistent feature over the past 30 years, as US politics has become ever further polarised.

During that period the same party has occasionally won all three branches of government, enabling them to pass key legislation. The Democrats did so 2020 and 2008, the Republicans in 2016 and 2004. Note, these four most recent examples were in general election years, suggesting that is possible for one party to get a clear result when turnout is at its highest.

Nevertheless, as it stands, the market points to more gridlock, albeit with control of the two chambers switching hands. The Democrats are trading at 1.75/7 for House of Representatives Control. implying a 59% chance, while the Republicans are overwhelming favourites for Senate Control at odds of 1.331/3 (75%).

Senate map is brutal for the Democrats

The 100 seats in the US Senate are re-elected after six year cycles, meaning around a third are up every two years. This can be particularly favorable to one party or another, and this year, that very much applies to the Republicans.

The Democrats start in control, leading 51-49. (The official number is 49-49, but two Independent Senators, Bernie Sanders and Angus King, vote with the Democrats). If the parties are tied 50-50, the Vice President casts the deciding vote.

If they could come out with a 50-50 tie and the Presidency, Democrats would be ecstatic. One seat, West Virginia, is all but gone. The retiring Joe Manchin was very much on the Right of the party, had drifted apart from the mainstream of the party and was even thinking of an Independent bid for the presidency. In his absence, this ultra-Trumpian state will likely elect a Republican by around a 40% margin.

The Democrats must therefore come out level among the rest. Yet they are heavily odds-on to lose Montana, where incumbent Jon Tester has performed miracles, but is expected to be blown away by Tim Sheehy in a red state which seems sure to vote for Trump by double-digit margins. He isn't that far behind in the polls, but ticket-splitting on that scale seems unlikely.

Ohio looks the most exciting race

Another red state where Democrats are on the defensive is Ohio, where Sherrod Brown is seeking a fourth term, challenged by Bernie Moreno - a Trump endorsement with some scandal hanging over him. This is a genuine 50/50 race and arguably the best market to follow besides the presidency.

They also have potentially tricky defences in five of the seven key swing states. In Arizona, Ruben Gallego is well ahead of Trump ally Kari Lake.

Likewise three incuments - Jacky Rosen against Sam Brown in Nevada, and Bob Casey versus David McCormick in Pennsylvania; Tammy Baldwin versus Eric Hovde in Wisconsin.

Michigan is an open seat, but Elissa Slotkin starts a heavy favourite against Mike Rogers.

Whilst in all of those, the Democrat has a chance in excess of 75%, nothing can be taken for granted in a general election with Trump on the ballot. Whereas the Republicans underperformed in the midterms, Trump attracts an extra batch of voters to the polls.

The three best Democrat longshots

Could the Democrats improve their mathematical prospect with a gain somewhere else? That isn't particularly likely, but three seats are on their radar. First in Texas, former pro footballer Colin Allred is giving Ted Cruz a close race. This state remains an outside target for the Democrats, given the growth of the Hispanic population and swing of suburban voters away from Trumpism. Also Cruz isn't a popular figure.

Less likely is Florida, which no longer seems a swing state. Here, arch-Trump ally Rick Scott is up against Debbie Mucarsel-Powell. Of interest here is Nate Silver's challenge to a GOP-aligned critic for a $100K bet on the margin being less than 8%. I'm sure he's right but that's nothing like winning the seat.

The really interesting state - a potential gamechanger - is Nebraska. The seat is open and in normal times, one would expect the Republican Deb Fischer to win the regular election easily in a red state. However, union-aligned Independent Dan Osborn is running her really close and could even be ahead. In the NE-02 district, which has voted Democrat and thus provided one critical electoral college vote, Osborn and Kamala Harris are both double-digits ahead. I assume he would vote with the Democrats if elected.

Superior Democrat organisation can regain the House

Regarding the House, I am confident of a Democrat victory, due to the ever starker differences in the way the respective parties operate. For months, we have been hearing about the Republican National Committee (now completely under control of the Trump family) is short on cash, having paid Trump's legal bills. They are highly disorganised.

In contrast, the Democrats have become a slick electoral machine. Harris, who is outraising Trump by big margins, is handing much of that cash to down-ballot candidates. They will be focused on all the key districts and I strongly believe that superior organisation makes all the difference. They start only 222-213 behind (or 221-214 if accounting for the sacked George Santos). That absurd scandal typified a chaotic session under GOP control. Expect them to pay the price.

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