A shrinking majority of Americans say Robert S. Mueller III’s investigation of Russian election interference and possible links to Donald Trump’s 2016 campaign should continue, according to a poll released Tuesday.

The Monmouth University poll finds 54 percent of Americans saying the special counsel’s investigation should continue, with support down from 60 percent in March and 62 percent in July. A 43 percent minority says the investigation should end, up six points since March and 10 points since last summer.

The results mirror two other recent polls finding a dip in confidence that Mueller’s investigation is fair toward Trump, although Mueller continues to receive significantly more positive ratings than negative.

Trump has long criticized the investigation as a “witch hunt,” and Tuesday he lambasted the New York Times’ publication of questions that Mueller was said to be interested in asking him as part of the probe into Russian interference and possible attempts to obstruct the inquiry.

Democrats and Republicans are deeply divided about whether the investigation should continue, and while a majority of independents say it should go on, the Monmouth poll suggests that support has declined. Support for continuing the investigation has slipped by eight points since March among Republicans (from 26 percent to 18 percent), while 82 percent of Democrats favor continuing the investigation, little changed from March.

Perhaps most important, independents’ support for continuing the Russia investigation declined from 63 percent in March to 54 percent in the new poll, an indication that criticisms of the probe have begun to catch on beyond Trump’s Republican base.

Separately, a Marist poll from April found 45 percent saying they thought the Mueller investigation was “fair,” down from a high point of 53 percent in February but similar to the 48 percent at the end of March. A still-smaller 30 percent said Mueller’s investigation was “not fair.”

And a Quinnipiac poll released last week found 54 percent of registered voters saying that Mueller was conducting a fair investigation, down slightly from 58 percent in March and a high of 60 percent in November, while 31 percent said it was unfair.

The latest surveys differ from polls earlier this spring that suggested support for Mueller’s investigation was steady or even rising. The Pew Research Center’s polling found 61 percent saying they were confident that Mueller would conduct a fair investigation, up from 55 percent in January. CNN-SSRS polling found almost no change in opinion, with between 47 percent and 48 percent approving of Mueller’s handling of the investigation in four polls from December to March, while between 33 percent and 35 percent disapproved.

Besides fairness or whether the investigation should continue, a mid-April Washington Post-ABC News poll found clear majority support for Mueller investigating three substantive questions, including 69 percent who supported his investigation of possible collusion between Trump’s presidential campaign and the Russian government in its attempts to influence the 2016 election.

A somewhat smaller 64 percent supported Mueller investigating Trump’s business activities, while 58 percent favored Mueller investigating allegations that Trump’s associates paid hush money to women who said they had affairs with him. It’s worth noting there has been no indication that Mueller’s team is exploring accusations by women about Trump’s personal conduct and no confirmation that his investigation has expanded to cover Trump business activities that do not relate to Russia.

Together, the polls suggest that while more Americans continue to support than oppose Mueller’s investigation, confidence in his probe has slipped in recent weeks. Polls in the coming weeks will tell whether the results are short-lived or mark a lasting trend.

The Monmouth University poll was conducted Thursday through Monday among a national sample of 803 adults reached by cellular and landline phones. Overall results have a margin of sampling error of plus or minus 3.5 percentage points.