While Hillary Clinton is leading Donald Trump among likely voters, many of the Republican nominee’s supporters agree with his repeated claims that the presidential election will be rigged, according to a new poll.

Clinton is beating Trump, 44% to 40%, according to a Reuters/Ipsos online poll conducted between Oct. 14 and Oct 20. That represents a closer margin than last week, when she led 44% to 37%.

The RealClear Politics polling average shows Clinton defeating Trump, 48% to 42%.

Trump has recently ramped up accusations that the presidential election will be rigged in Clinton’s favor, presenting without evidence a claim that undermines the legitimacy of the democratic process. Election officials and members of both parties have condemned and dismissed Trump’s claims.

But nearly 70% of Republicans surveyed in the Reuters/Ipsos poll said a victory by Clinton would be the result of illegal voting or vote rigging. The poll also found that just half of Republicans said they would accept Clinton as their president.

The poll, conducted online, surveyed 1,640 people.