US Election: Do vice president picks affect who wins?

• Do VP picks affect the outcome of US elections?

• Will Walz or Vance help or hinder Harris and Trump?

• Follow our 2024 US Election live blog

• See US election odds as you've never seen them before

The presidential debate between Kamala Harris and Donald Trump was pivotal in the election winner market on the Betfair Exchange as the former overtook the latter to become favourite to win the White House.

That is almost certain to be the last time the Democratic and Republican candidates for president meet in a live debate.

With voters going into election day having had only one chance to see Harris and Trump face each other, the vice presidential debate between the Democratic candidate Tim Walz and Republic JD Vance could take on extra significance.

Walz v Vance debate is on 1 October

The pair will meet in a televised debate in New York City on 1 October and, if the race so far is anything to go by, they will arrive with very different agendas.

Vance was chosen to be Trump's running-mate in the summer and almost immediately started making headlines with unpopular comments about childless women, abortion and more sensitive topics.

A week before the Harris v Trump debate, our politics betting expert cited Vance's poor performance as one reason why Harris could win the election.

Paul wrote: "Whilst one wouldn't generally expect vice presidential picks to be a key determinant, the gap between Tim Walz and J.D. Vance is stark. The Democrat has a +4.5 approval, compared to -10.5 for the Republican. Vance is the most unpopular running mate in history."

Some commentators feared Walz was too liberal to be a successful running-mate for Harris. Bu as soon as her choice was announced it started to look like a good one with the Minnesota governor delivering powerful speeches and voters appearing to warm to his relatable Midwestern persona.

Walz will try to bolster the impression that he is a serious man, who understands the concerns of ordindary Americans in the debate on 1 October, while Vance could see it as an opportunity to show the electorate that he is not as extreme as some of the soundbites would have voters believe.

Will Harris be next VP to become president?

John Nance Gardner, who serve as vice president under Franklin D. Roosevelt, famously said the job was "not worth a bucket of warm piss". That may sound an odd way to talk about the role of ostensibly the second most powerful person on earth. But it is how the vice president has been perceived and portrayed in popular culture, most notably in the TV series Veep, in which Julia Louis-Dreyfus plays a hapless vice president.

Still, Louis-Dreyfus's vice president goes on to get the top job, as many vice presidents have done in reality. In fact, if Harris wins the election on 5 November she will be the 16th VP in history to make the step up to president. They include the current president Joe Biden, who served eight years as Barack Obama's VP, George H.W. Bush, Gerald Ford, Richard Nixon and Lyndon Johnson.

When Harris was announced as Biden's running mate four years ago, it was widely assumed that she would be the Democratic candidate for president in 2024, due to Biden's age. That is exactly what has happened, even though Biden intended to seek a second term and to be persuaded to stand aside for his younger colleague.

Palin into insignificance

Vice presidential candidates come and go, especially if they are on a losing ticket. Few on this side of the Atlantic would remember Joe Lieberman, Paul Ryan or Tim Kaine. But I bet you remember Sarah Palin.

She made a big splash as John McCain's running mate in 2008. The Republican nominee for president plucked the gun-toting Alaskan from relative obscurity and she proved to be a firebrand on the campaign trail. Unfortunately for the Republicans, it didn't have the desire effect and Obama romped to victory.

Palin hung around for a few years after that, with a run for the top job mooted in 2012, before leaving the limelight.

Former-Republican VP Cheney is voting for Harris

The last vice president before Biden to serve two terms was Dick Cheney. He was part of the second Bush administration from 2000 to 2008. He epitomised the neo-Conservativism of the then American government but recently announced that he would be voting for Harris.

Cheney remains a divisive figure and there are some on the left who do not wish to see the Democratic candidate embraced by him. But does he retain influence over the kind of Republicans who would rather Trump was not their party's candidate again? We will see.

Now read Betfair US election live blog for the latest betting news