The public’s opinion of special counsel Robert Mueller has dropped to an all-time low as President Trump and his allies continue their attacks on the former FBI director investigating possible collusion between Trump’s campaign and Russia, a new poll shows.

A Politico/Morning Consult poll released Wednesday found that Mueller’s public image has been tainted most among Republicans. Fifty-three percent have a negative view of Mueller, who is a Republican, representing a 26-point drop from a year earlier when the poll began asking voters about their views on the investigator.

Democrats and independents have also soured on Mueller. Twenty-four percent of Democrats have an unfavorable view of Mueller, as did 33 percent of independents.

Trump and his lawyer Rudy Giuliani have directed constant attacks at Mueller as the investigation, which the president has called a "witch hunt" and “unconstitutional,” enters its second year.

Trump, however, did not escape voters’ scrutiny in the poll. Forty-eight percent believe he has tried to obstruct or impede Mueller’s investigation, a slight increase from an early February poll on the topic. Seventy-nine percent of Democrats view Trump as trying to obstruct the investigation, though 70 percent of Republicans said Trump wasn’t interfering in the probe.

The poll was conducted June 7-10 and surveyed 1,994 registered voters. It has a margin of error of plus or minus 2 percentage points.