WASHINGTON — President Donald Trump's disapproval rating has hit a high point of 60 percent, according to a new Washington Post-ABC News poll that also finds that clear majorities of Americans support the special counsel's Russia investigation and say the president should not fire Attorney General Jeff Sessions.

At the dawn of the fall campaign sprint to the midterm elections, which will determine whether Democrats retake control of Congress, the poll finds a majority of the public has turned against Trump and is on guard against his efforts to influence the Justice Department and special counsel Robert Mueller's wide-ranging probe.

Nearly half of Americans, 49 percent, say Congress should begin impeachment proceedings that could lead to Trump being removed from office, while 46 percent say Congress should not.

And a narrow majority — 53 percent — say they think Trump has tried to interfere with Mueller's investigation in a way that amounts to obstruction of justice; 35 percent say they do not think the president has tried to interfere.

Overall, 60 percent of Americans disapprove of Trump's job performance, with 36 percent approving, according to the poll. This is only a slight shift from the last Post-ABC survey, in April, which measured Trump's rating at 56 percent disapproval and 40 percent approval.

The new poll was conducted Aug. 26 to 29, in the week after former Trump campaign manager Paul Manafort was convicted of federal tax and bank fraud and after former Trump attorney Michael Cohen pleaded guilty and implicated the president in illegal payments to silence women who alleged sexual encounters with Trump.

The four-month gap between Post-ABC polls makes it difficult to attribute the modest uptick in disapproval of Trump to specific events. Other public polls have shown Trump's disapproval rating in the low- to mid-50s and have not tracked a rise since the Manafort conviction and Cohen guilty plea.

Trump has tried to rally support for Republican candidates in the Nov. 6 elections by pointing to his economic record. This week's poll finds that despite the president's unpopularity with voters, he gets better ratings when it comes to the economy: 45 percent of Americans approve and 47 percent disapprove of Trump's handling of the economy.

Trump's overall popularity breaks down along lines of partisanship, ethnicity and gender, according to the poll. While 78 percent of Republicans approve of his performance, 93 percent of Democrats and 59 percent of independents disapprove. More men support him than women, and while 45 percent of whites back him, 19 percent of nonwhites approve.

The poll finds that there are clear limitations to Trump's efforts all summer to politicize and discredit the Russia investigation. The president has fired a near-daily barrage of tweets labeling the probe a "witch hunt" and attacking the credibility of Mueller and several current and former Justice Department officials.

But 63 percent of Americans support Mueller's investigation of Russian interference in the 2016 election, with 52 percent saying they support it strongly; 29 percent oppose the probe.

Opinions on Mueller's work also break down on partisan lines, with 61 percent of Republicans opposing the probe but an even larger 85 percent of Democrats expressing support. Among independents, however, a two-thirds majority of 67 percent back the investigation.

Trump has complained that Manafort was treated unfairly by Mueller's prosecutors, and after a jury convicted Manafort earlier this month the president tweeted that he felt "very badly" for him.

But 67 percent of Americans think Mueller's case against Manafort was justified, while 17 percent say it was unjustified, according to the poll.

Trump's praise of Manafort has stirred speculation that he might pardon his former campaign chairman, but the poll finds that it would be a political land mine for the president. Two-thirds of Americans oppose Trump pardoning Manafort — 53 percent strongly oppose it — and 18 percent support a pardon.

Trump has ratcheted up his public attacks on Sessions in recent weeks and has consulted his personal attorneys and other advisers about firing the attorney general, whom he has viewed as insufficiently loyal after Sessions recused himself last year from overseeing the Russia investigation because of a conflict of interest.

But the public is squarely behind Sessions. Sixty-four percent of Americans do not think Trump should fire Sessions, with 19 percent saying he should and 17 percent saying they have no opinion. Nearly half of Republicans, 47 percent, say Trump should not fire the attorney general, with 31 percent saying he should.

Just under a quarter of Americans, 23 percent, say they agree with Trump's criticisms of Sessions for allowing the Mueller investigation to proceed, while 62 percent say they side with Sessions, who has said he is following the law.

Two-thirds of Americans say they had read or heard at least some of the news about Cohen's guilty plea to eight violations of banking, tax and campaign finance laws, though less than a quarter heard "a great deal" about the news.

Cohen told a federal judge last week that before the 2016 campaign, then-candidate Trump directed him to pay off two women to keep their stories of alleged affairs with Trump from becoming public.

The poll finds that 61 percent of Americans think that Trump committed a crime if he did direct Cohen to make the payments, while 31 percent say he did not commit a crime.

Democrats are hoping to retake control of one or both houses of Congress in November's elections. If they do, party leaders will face pressure from their energized base to use congressional oversight committees to investigate potential misconduct by the president and his administration, as well as perhaps begin impeachment proceedings.

The survey finds a clear partisan divide on the issue. While 75 percent of Democrats say Congress should begin impeachment hearings, 82 percent of Republicans say lawmakers should not. Among independents, 49 percent support impeachment while 46 percent oppose it.

The Post-ABC poll was conducted among a random national sample of 1,003 adults reached on conventional and cellphones; the margin of sampling error for overall results is plus or minus 3.5 percentage points.