An increasing number of registered voters believe Russian hackers helped President Trump win last year's election, according to Fox News poll results released Wednesday evening.

The May 21-23 survey found 44 percent of people think Russia attempted to influence the presidential election to help Trump, not rival Hillary Clinton. Last December, fewer than one-third of respondents said the Russians tipped the scales in Trump's favor. Forty-nine percent said Russia had no effect on the race, down 10 percentage points from 59 percent in December.

Public skepticism over Trump's firing of former FBI Director James Comey, whose agency was investigating Russia's interference in the election, was also high. Three-in-five people said Trump fired Comey because the agency's probe was harming the president, while only 29 percent said Trump terminated Comey because he was harming his own agency.

Almost the same number of respondents -- 43 percent to 45 percent -- think Robert Mueller, recently appointed as special counsel of the FBI's Russia investigation, will or will not find that Trump's campaign associates coordinated with Russia, respectively.

The poll was conducted by landline and cellphone with 1,011 registered voters nationwide by Anderson Robbins Research and Shaw & Company Research. The poll had a margin of error of plus or minus 3 percentage points.