A majority of Americans say they oppose calls for Congress to launch impeachment proceedings against President Trump in the wake of special counsel Robert S. Mueller III’s investigation into Russian interference in the 2016 election and whether the president sought to interfere with the probe, according to a Washington Post-ABC News poll.

Thirty-seven percent of Americans favor starting the process that could lead to impeachment, a slight dip over the past month, while 56 percent say they oppose the idea, about the same as a month ago.

House Democrats are grappling with the question of how to proceed in light of Mueller’s findings and the public release of the redacted report, which detailed multiple examples of potential obstruction of justice.

The new survey highlights the dilemma faced by House Speaker Nancy Pelosi (D-Calif.) and other leaders in her caucus: While party leaders have sought to tamp down impeachment talk, worried that engaging in such a process would backfire in the 2020 election, their political base supports it.

Roughly 6 in 10 Democrats say they support the initiation of such an investigation in the House, with 53 percent saying they hold that view strongly. Meanwhile, nearly 9 in 10 Republicans oppose impeachment, with 78 percent strongly opposed.

About 6 in 10 independents are against impeachment now, and independents are more opposed today than they were when measured in a January poll — a sign of the potential political danger for Democrats as they seek to win back key centrist voters in their goal of beating Trump next year.

House Democratic leaders have said they will pursue various investigations, including possible obstruction of justice by the president, although they have so far stopped short of embracing the idea of impeachment. Some Democratic presidential candidates say the Mueller report justifies pursuing such proceedings, however, and are urging House leaders to move ahead.

Trump has repeatedly denounced the Mueller investigation, both as it was taking place and since, calling the matter a “witch hunt” and allegations of collusion a “hoax.” The president’s credibility is called into question by a majority of Americans, with 58 percent saying they believed he has lied to the public about matters under investigation by the special counsel. One in 3 say they believe he has told the truth.

Overall, the Post-ABC survey finds that partisan allegiance colors the views of Americans about what the Mueller report found, what it means and what should be done as a result. But on one question there was agreement across the political spectrum.

Mueller receives positive marks from Democrats and Republicans, with 53 percent of Democrats, 56 percent of Republicans and 51 percent of independents saying they believe the report was fair and evenhanded. Fewer than 3 in 10 of any partisan group say the report was not fair. That marks a significant shift in attitudes since January, when barely one-fifth of Republicans (22 percent) thought Mueller’s report would be fair, while 62 percent of Democrats had confidence in the special counsel to issue an evenhanded report.

[Read full poll results | How the poll was conducted ]

Mueller’s report said the investigation did not establish that there was a conspiracy among Trump campaign officials to work with the Russians to sabotage the 2016 election, though there were many contacts between campaign associates and Russians with ties to their government detailed in the report.

On the question of obstruction, the report cited multiple examples in which Trump appeared to seek to interfere with Mueller’s investigation, but Mueller said he believed that Justice Department policy that says the president cannot be indicted in office also meant he should draw no conclusion as to whether the president committed a crime. For that reason, the investigation did not offer a conclusion as to whether the president’s actions constituted obstruction. Attorney General William P. Barr declared that the findings did not justify a criminal charge of obstruction.

The evidence of interference presented in the report has spurred Democrats to push for documents, hearings and testimony from current or former Trump administration officials, action that is seen as a prelude to possible impeachment proceedings. Trump said earlier this week he opposes such testimony and will fight any subpoenas issued by House Democrats, setting up a lengthy legal clash and a standoff between the executive and legislative branches.

Trump has declared “total exoneration” by the Mueller report, despite the clear statement in the report that investigators did not reach that conclusion. Asked their view of whether the report cleared Trump of all wrongdoing, 53 percent of Americans say it did not while 31 say it did. Among Republicans, 61 percent say they believe Mueller’s investigation cleared Trump of all wrongdoing, while 87 percent of Democrats say it did not.

On the question of whether Trump tried to obstruct Mueller’s probe, 47 percent say he did try to interfere while 41 percent say he did not. This finding masks lopsided opinions among partisans. Roughly 8 in 10 Democrats say Trump tried to interfere with the investigation in a way that amounts to obstruction of justice, while almost 8 in 10 Republicans say Trump did not do this.

In the current Post-ABC poll, Trump’s overall approval rating stands at 39 percent, a statistically insignificant change from January, when it was 37 percent. Among registered voters, his approval rating is 42 percent. His disapproval rating among all adults (as well as among registered voters) is at 54 percent, down slightly from 58 percent in January. At the time of the earlier survey, Trump and congressional Democrats were in a dispute over funding for a border wall, which had led to a partial shutdown of the government.

A 58 percent majority of Americans say the Mueller report has not changed their impression of the Trump administration. Among those whose views have changed, 23 percent say they view the administration more negatively while 11 percent view it more positively.

Slightly more than 1 in 3 Americans say the Mueller investigation makes them less likely to support Trump’s reelection in 2020, while 14 percent say they are more likely and a plurality of 46 percent say the findings are not a factor in their choice for the next election. Unsurprisingly, the biggest block of people who say they are more likely to oppose Trump for reelection is among Democrats.

The survey finds a clear partisan split on the question of whether, based on the Mueller report and other available information, the Russian efforts to interfere in the 2016 election undermined the legitimacy of the outcome. Overall, 49 percent say it did not rise to that level, while 42 percent say the Russian role undermined the election’s legitimacy. Roughly 7 in 10 Democrats say it did, while about 8 in 10 Republicans say it did not.

Looking forward, 76 percent of Democrats say possible Russian interference represents a threat — major or not so major — to the legitimacy of the 2020 election, while 61 percent of Republicans say it does not threaten its legitimacy.

Support for impeachment is higher among Americans younger than 40 than among those older. It is highest among African Americans, 69 percent of whom say they favor it. The strongest opposition to impeachment comes from white evangelical Christians, white men without college degrees, white mainline Protestants and white Catholics. Support is higher in the Northeast and in the West than it is in the South and the Midwest.

The Post-ABC poll was conducted by telephone April 22-25 among a random national sample of 1,001 adults, with 65 percent reached on cellphones and 35 percent on landlines. Overall results have a margin of sampling error of plus or minus 3.5 percentage points.

Emily Guskin contributed to this report.