The Washington Post reported that President Biden is growing more resentful of his choice to halt his presidential campaign this past summer.

According to several people acquainted with the president’s thinking, the president feels that he would have won the election if he had remained in the race, despite his dismal debate performance in June and plummeting approval ratings that forced him out.

In the days after the June 27 debate, in which the president spoke haltingly and seemed exhausted, Biden was inundated with requests to resign from Democratic lawmakers and powerful funders. Important Hollywood donors like George Clooney also started to stop contributing to the president’s reelection campaign.

After former President Barrack Obama demanded a “open process,” Biden left the contest on July 21 and nearly immediately supported Vice President Kamala Harris.