As Republicans and Democrats gear up for the vice-presidential debate next week, exclusive polling shows that this is an event that has the potential to change everything.

Two-thirds of Democrats believe the vice-presidential candidate has a significant impact on the overall presidential ticket, according to polling from Prolific for The Independent.

Republican vice-presidential nominee JD Vance is set to debate Democratic VP pick Tim Walz this Tuesday, October 1 at 9pm ET.

Three out of four Americans (75 per cent) are planning to watch the VP debate, according to the poll, which surveyed a nationally representative sample of 2,000 participants on the Prolific platform on September 22.

Vance has said he “doesn’t have to prepare that much” for his first head-to-head — despite reports to the contrary in The New York Times, which suggested he will spend several days this week in preparation.

Though the VP debate might appear to live in the shadow of this month’s Trump-Harris match-up, the polls suggest that, for many voters, the event will be far from insignificant.

As to whether debates themselves have a significant impact on how voters lean, our poll shows that a third (30 per cent) of viewers had a more positive opinion of Kamala Harris following the presidential debate earlier this month.

This includes 21 per cent of independent voters, who constitute a crucial factor in the outcome of the election.

For Donald Trump, overall most respondents said their opinion had stayed the same, or worsened (14 per cent), including independents.

Just over half of Americans (56 per cent) believe that the vice-presidential candidate has a significant impact on the overall ticket. This increases to two-thirds (66 per cent) of Democrats, who place a high value on the choice of VP.

Considering that the Democratic candidate Harris is the current vice-president, this may be unsurprising.

In fact, when the incumbent president Joe Biden ran in 2020, there was much anticipation around his choice of running mate, with specific emphasis on his decision to choose a woman of color as his VP.

This year, Harris’s campaign was strategic in choosing her No 2, with the final lineup consisting of various white men in the Democratic Party before Minnesota governor Walz was selected.

Republicans are evenly split on the VP issue, with 49 per cent saying that the VP choice is significant and 51 per cent saying it is not.

In 2016, Trump picked the then governor of Indiana, Mike Pence, as his running mate, strategically bolstering his own lack of experience by choosing a mainstream conservative politician who had decades of experience in the House. But this year, he has done the opposite, choosing the much younger and inexperienced Vance, who first went into office just a year ago.

Andrew Gordon, senior research consultant at Prolific, said: “VPs are traditionally seen as ancillary to the presidential candidate in US elections, but this time around we’re seeing a larger impact than usual. The polling data showing that two-thirds of Democrats say the VP choice will affect their vote highlights this, and may be reflective of an era where concerns about continuity of leadership or health of candidates may be heightened — especially with older presidential candidates like Biden and Trump.”

Six former vice-presidents have gone on to become president, while 19 have run for the top spot, meaning that Tuesday’s debate could well showcase a future presidential candidate.

The most recent VP-to-president pipeline success story is current president Biden, who enjoyed a close public relationship with Barack Obama during the two terms he spent as his right-hand man.

Gordon also noted that previous polls have suggested that only 2 per cent of voters tend to change their behavior at the ballot box as the result of a debate. Nevertheless, he added: “It’s a warning shot to the Republican campaign that this pattern of improved perceptions of Harris and reduced perceptions of Trump held for voters in all seven major swing states — critical areas where Trump needs to be winning voters to his side.

“The VP debate could therefore be of considerable importance this election cycle in shoring up moderate Republican support, in light of the perceived weak performance from Trump in the ABC presidential debate.”