While focus is on presidential election, US Congress with razor-thin majorities will shape agenda

While the focus has been on the presidential election, it will be the results of US Congressional polls that will determine if the winner's agenda can be implemented and if it can act as a check on the president.

The majorities in the Senate and the House of Representatives are razor thin, reflective of the polarised nation.

An aggregation of generic Congressional polls by RealClear Polling (RCP) gives the Republicans a 0.9 per cent majority, while the New York Times version has the two parties tied at 48.

The Democratic Party candidates in general are putting distance from President Joe Biden and in many of the tossup constituencies, and they are disavowing -- like Vice President Kamala Harris -- their radical positions like open borders or cutting police budgets.

On the Republican side, candidates are giving up calls for national anti-abortion laws and playing down their association with controversial conservative organisations like the Heritage Foundation.

The Republicans have 49 seats in the Senate to the Democrats' 47, but three of the four Independents act jointly with the Democrats giving them a tally of 50 and Vice President Harris as the presiding officer of the Senate gives the party its majority with her tie-breaking vote.

Senators serve for six years and 34 will complete their terms next year putting those seats in play in this year's election.

According to RCP, 15 of them are not solidly with either party, but lean to them to varying degrees, with seven remaining as tossups.

Based on polls, RCP on Wednesday showed Republicans picking up two seats for a 51-seat majority.

One of them is the seat of Joe Manchin, who was elected as a Democrat from West Virginia but became an Independent backing the party this year, and is retiring.

The state’s Republican Governor Jim Justice who is running for the seat has a 34 per cent lead in a poll assuring him of a victory.

The other is Montana, where Republican Tim Sheehy leads by 6.5 per cent according to RCP aggregation of polls.

But RCP also shows that with Texas Republican Senator Ted Cruz moving to the tossup category his party could be locked in a 50-seat deadlock if he loses.

Should that happen, the next vice president would again have the final say in the Senate.

In the House, the Republicans who recaptured the majority in 2022 have 220 seats and the Democrats 212, and with 218 needed for a majority in a full House of 435 a change in two seats can tip the scales.

Even with the slim majority that the Republicans have, the leaders couldn’t always accomplish their goals because any revolt by a small number of members throws them off.

The future of the House now depends on Democratic Party candidates like Indian American doctor Amish Shah, who is trying to take back a seat his party held in Arizona and lost by just 3,195 votes in 2022.

Like that seat, there are several around the country in what were traditionally Democrat-leaning areas that went Republican in the last election mainly because of issues like crime and immigration.

The Cook Political Report, which analyses a wide range of data and not just polls, reported that 25 seats are tossups, 207 solidly Republican or with an edge, and 203 with Democrats having a solid hold or an edge.

FiveThirtyEight, a political and electoral data analysis publication affiliated with ABC, reported that "fresh polls of the Congressional generic ballot are flashing a warning sign for Democrats. Their margin has slipped to just +0.5 points over the Republicans, down from a peak of +2.6 in early September".

According to 1,000 computer simulations it ran with different scenarios, 527 showed Republicans controlling the House and Democrats 473.

"The national popular vote does not matter for deciding who controls the majority. Our forecast sees the House coming down to a small number of competitive seats -- currently, we rate fewer than 30 seats as Toss-up, Lean Democratic or Lean Republican seats," it said.

Yet another forecast by The Hill, gives the Republicans 219 seats to Democrats’ 216, with the Republicans ultimately having an 8 per cent edge over Democrats in controlling the House.