Former President Donald Trump has seen his chances of winning the 2024 presidential election increase in recent hours, driven by changes in Pennsylvania and Arizona, according to a prominent bookmaker.

At 4:20 a.m. ET on Tuesday, British gambling company Betfair gave the Republican candidate odds of 4/6 (60 percent) for victory, compared to 6/4 (40 percent) for his Democratic rival, Vice President Kamala Harris. By 12:50 PM ET, however, Trump’s odds were down to 5/8 (61.5 percent), while Harris’s were extended to 8/5 (38.5 percent).

Voters are heading to the polls in the United States for what recent polls show will be a razor-thin contest. An analysis of recent polls released Tuesday morning by election website 538 shows Harris 1.2 points ahead of Trump in the national election, with 48 percent of the vote to 46.8 percent. However, because of the Electoral College system, Trump could lose the popular vote but still win the election, as he did in 2016 against Hillary Clinton.

The change in overall Betfair odds since this morning was driven by an improvement in Trump’s odds in the battleground states of Pennsylvania and Arizona.

In Pennsylvania, which has 19 Electoral College votes, Trump’s odds of winning rose from 52 percent on Tuesday morning to 58 percent, according to Betfair. Over the same period, Trump’s odds of victory in Arizona, which received 11 Electoral College votes, improved from 73 percent to 78 percent.

Betfair spokesperson Sam Rosbottom said this NewsweekBettors’ confidence in the former president continues to grow as Republicans appear to inch closer to victory in two key swing states – Arizona and Pennsylvania.

“Republicans now have a 2/7 (78 percent chance) of winning in Arizona and a 5/7 (58 percent chance) in Pennsylvania,” Rosbottom said. “Trump’s chances have narrowed in both states in recent hours. He is ahead in five of the seven swing states.”

Newsweek contacted the Trump and Harris campaigns by email on Tuesday for comment.

An artificial intelligence-based model created by Aaru for media outlet Semafor has Harris favored to win five of the seven battleground states.

The model, which relies on the creation of “a thousand or more” AI bots for each state representing voters, concluded that the vice president is most likely to win in Michigan, Nevada, Pennsylvania and Wisconsin. However, Trump led in Arizona, Georgia and North Carolina. If all other states repeat their 2020 election results, that would be enough to give Harris victory.

According to the final election forecast released by 538 on Tuesday, Harris had a 50 percent chance of winning the election, just ahead of Trump at 49 percent. The data was based on 1,000 election simulations and last updated at 6 a.m. ET.

However, a Decision Desk HQ/The Hill forecast published Tuesday gave Trump a 54 percent chance of victory, compared to Harris’ 46 percent. The average projection had the Republican winning with 276 Electoral College votes (270 are needed to win), ahead of Harris’ 262.

Speaking to reporters in Palm Beach, Florida, Trump stressed as he cast his vote that he would concede if he lost a “fair” election.

“If I lose an election, if it’s a fair election, I would be the first to acknowledge that,” he said. “So far I think it has been fair.”

Trump continues to maintain that the 2020 presidential election was stolen from him through fraud, although the claim has been repeatedly rejected by courts and by independent election experts.