Support for impeaching President Donald Trump has only solidified among the Democratic base since the release of the former special counsel Robert Mueller's report, new INSIDER polling shows.

When INSIDER first polled impeachment on April 18-19 — right when the Mueller report was released — we asked, "Generally speaking, do you think that pursuing impeachment of President Donald Trump is a good use of House Democrats' time?"

From May 31 to June 1, INSIDER polled the same question, slightly changing the phrasing to ask whether impeachment "was a good use of the House of Representatives' time" more generally, instead of just House Democrats.

In the weeks since the release of the Mueller report, and after Mueller delivered a press conference further re-iterating his findings, support for impeachment has only increased among the Democratic base.

28% (+6) of neither liberal nor conservative respondents thought impeachment was an "extremely" or "very good" use of time.

of neither liberal nor conservative respondents thought impeachment was an "extremely" or "very good" use of time. 31% (-1) of slightly liberal respondents agreed.

(-1) of slightly liberal respondents agreed. 44% (+10) of moderately liberal respondents agreed.

of moderately liberal respondents agreed. 62% (+12) of very liberal respondents agreed.

Support for impeachment is still low among self-identified conservative respondents, with 14% of slightly conservative, 12% of moderate conservative and 17% of very conservative respondents saying that impeachment is an "extremely" or "very good" use of the House's time.

It's worth noting that the framing of the question may have changed the tenor of the response. However, given that the shift was not uniformly observed — how the opinions of slightly liberal respondents held steady whereas the beliefs of both their more and less liberal counterparts lurched more in favor — it's worth a comparison even if it's simply one survey and not a confirmed shift.

Rep. Rashida Tlaib of Michigan first introduced a resolution in favor of impeachment in late March with just a few cosponsors, but the release of the former special counsel Robert Mueller's report from his nearly two-year-long investigations and its aftermath have increased the appetite for impeaching Trump.

The report did not come to a "traditional prosecutorial decision" as to whether Trump obstructed the Mueller probe and other federal investigations involving him and other White House officials, but laid out 11 possible incidents of obstruction and left it to Congress to decide.

Read more: Democrats are divided as ever on impeachment after Mueller punted the question to Congress

The fervor for impeachment has only intensified as the Trump administration ramped up its stonewalling of Congress' attempts to investigate Trump since the report's release.

In the past month, the White House successfully ordered former White House counsel Don McGahn to defy a subpoena to testify before the House Judiciary Committee, and the Treasury Department went to court to refuse to hand over Trump's tax returns to the Financial Services Committee.

On May 29, Mueller gave a press conference at the DOJ announcing his formal resignation, re-iterating the conclusions of his report's findings, and declining to voluntarily testify before Congress, which prompted more congressional Democrats and 2020 presidential candidates to come out in support of Congress beginning an impeachment inquiry.

Mueller made it explicitly clear that the report did not exonerate Trump, and that his office had no ability to charge Trump with a crime given existing DOJ policy prohibiting prosecutors from indicting a sitting president — leaving the next steps up to Congress.

Read more: The House Majority Leader just said a lot more Trump administration officials could be held in contempt of Congress next week

In the administration's most recent re-buff of congressional oversight, the White House ordered former White House communications director Hope Hicks and Annie Donaldson, who served as chief of staff to former White House counsel Don McGahn, not to comply with subpoenas from the House Judiciary Committee. (Hicks ended up turning over some documents from her time working on the Trump campaign.)

While Speaker Nancy Pelosi and other top Democrats including Majority Leader Steny Hoyer and Caucus Chair Hakeem Jefferies say they believe an impeachment inquiry would divide the country and end up playing into Trump's hands, a stronger consensus is forming among other Democrats that impeachment is a necessary next step.

Read more:

Mueller says he won't make any more public statements on the Russia probe, but his own words bolster the case for Democrats to have him testify before Congress

Nancy Pelosi said she doesn't want to impeach Trump because that would be giving him what he wants

Trump says he 'can't imagine the courts allowing' him to be impeached, even though it's up to Congress, not the courts

SurveyMonkey Audience polls from a national sample balanced by census data of age and gender. Respondents are incentivized to complete surveys through charitable contributions. Generally speaking, digital polling tends to skew toward people with access to the internet. SurveyMonkey Audience doesn't try to weight its sample based on race or income. Total 1,107 respondents collected May 31 to June 2, 2019, a margin of error plus or minus 3.1 percentage points with a 95% confidence level.