WASHINGTON (Reuters) - Congressional Democrats on Friday took legal action to get hold of all of U.S. Special Counsel Robert Mueller’s evidence from his inquiry into Russian meddling in the 2016 election, as the probe’s findings hit President Donald Trump’s poll ratings.

The number of Americans who approve of Trump dropped by 3 percentage points to the lowest level of the year following the release of a redacted version of Mueller’s report on Thursday, according to a Reuters/Ipsos online opinion poll.

Mueller did not establish that the Trump campaign coordinated with Russians but did find “multiple acts by the President that were capable of exerting undue influence over law enforcement investigations.”

While Mueller ultimately decided not to charge Trump with a crime such as obstruction of justice, he also said that the investigation did not exonerate the president, either.

U.S. House of Representatives Judiciary Committee Chairman Jerrold Nadler, a Democrat, issued a subpoena to the Justice Department to hand over the full Mueller report and other relevant evidence by May 1.

“My committee needs and is entitled to the full version of the report and the underlying evidence consistent with past practice. The redactions appear to be significant. We have so far seen none of the actual evidence that the Special Counsel developed to make this case,” Nadler said in a statement.

The report provided extensive details on Trump’s efforts to thwart Mueller’s investigation, giving Democrats plenty of political ammunition against the Republican president but no consensus on how to use it.

The document has blacked out sections to hide details about secret grand jury information, U.S. intelligence gathering and active criminal cases as well as potentially damaging information about peripheral players who were not charged.

Six top congressional Democrats led by House Speaker Nancy Pelosi and Senate Minority Leader Chuck Schumer rejected Attorney General William Barr’s offer to give them access to a less-redacted version of the report. In a letter to Barr, they repeated their demand the full report be given to Congress, but said they were open to “a reasonable accommodation.”

Democratic leaders have played down talk of impeachment of Trump just 18 months before the 2020 presidential election, even as some prominent members of the party’s progressive wing, notably U.S. Representative Alexandria Ocasio-Cortez, promised to push the idea.

U.S. Senator Elizabeth Warren became the first major contender for the Democratic 2020 presidential nomination to call for the start of impeachment proceedings, saying on Twitter that “the severity of this misconduct” demands it.

“To ignore a President’s repeated efforts to obstruct an investigation into his own disloyal behavior would inflict great and lasting damage on this country,” she said.

‘CRAZY MUELLER REPORT’

Trump, who has repeatedly called the Mueller probe a political witch hunt, lashed out again on Friday.

“Statements are made about me by certain people in the Crazy Mueller Report...which are fabricated & totally untrue,” Trump wrote on Twitter.

He seemed to be referring to former White House counsel Don McGahn who was cited in the report as having annoyed Trump by taking notes of his conversations with the president.

“Watch out for people that take so-called “notes,” when the notes never existed until needed.” Trump wrote, “it was not necessary for me to respond to statements made in the “Report” about me, some of which are total bullshit & only given to make the other person look good (or me to look bad).”

Phone conversations between the president and McGahn in June 2017 were a central part of Mueller’s depiction of Trump as trying to derail the Russia inquiry. The report said Trump told McGahn to instruct the Justice Department to fire Mueller. McGahn did not carry out the order.

In analyzing whether Trump obstructed justice, Mueller revealed details about how the president tried to fire him and limit his investigation, kept details of a June 2016 meeting between senior campaign officials and a Russian under wraps, and possibly dangled a pardon to a former adviser.

According to the Reuters/Ipsos poll of 1,005 adults conducted Thursday afternoon to Friday morning, 37 percent of people approve of Trump’s performance in office - down from 40 percent in a similar poll conducted on April 15 and matches the lowest level of the year. The poll has a credibility interval, a measure of precision, of 4 percentage points.

Representative Doug Collins, the top Republican on the House Judiciary Committee, said the Democrats’ subpoena “is wildly overbroad” and would jeopardize a grand jury’s investigations.

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The Mueller inquiry laid bare what U.S. intelligence agencies have described as a Russian campaign of hacking and propaganda to sow discord in the United States, denigrate 2016 Democratic candidate Hillary Clinton and boost Trump.

Russia said on Friday that Mueller’s report did not contain any evidence that Moscow had meddled. “We, as before, do not accept such allegations,” Kremlin spokesman Dmitry Peskov said.

Asked on Friday about Russian interference in 2016, U.S. Secretary of State Mike Pompeo said in Washington that “we will make very clear to them that this is not acceptable behavior.”

Trump has tried to cultivate good relations with Russian President Vladimir Putin, and came under heavy criticism in Washington last year for saying after meeting Putin that he accepted his denial of election meddling, over the conclusions of U.S. intelligence agencies.

Half a dozen former Trump aides, including former campaign chairman Paul Manafort, were charged by Mueller’s office or convicted of crimes during his 22-month-long investigation. The Mueller inquiry spawned a number of other criminal probes by federal prosecutors in New York and elsewhere.

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OBSTRUCTION

One reason it would be difficult to charge Trump is that the Justice Department has a decades-old policy that a sitting president should not be indicted, although the U.S. Constitution is silent on whether a president can face criminal prosecution in court.

A paragraph in the report is at the heart of whether Mueller, a former FBI director, intended Congress to pursue further action against Trump.

“The conclusion that Congress may apply the obstruction laws to the President’s corrupt exercise of the powers of office accords with our constitutional system of checks and balances and the principle that no person is above the law,” Mueller wrote.

Republican Collins said Democrats had misconstrued that section of the report to suit their anti-Trump agenda.

“There seems to be some confusion...This isn’t a matter of legal interpretation; it’s reading comprehension,” Collins wrote on Twitter.

“The report doesn’t say Congress should investigate obstruction now. It says Congress can make laws about obstruction under Article I powers,” Collins said.

Nadler told reporters on Thursday that Mueller probably wrote the report with the intent of providing Congress a road map for future action against the president, but the Democratic congressman said it was too early to talk about impeachment.

But the House Oversight Committee’s Democratic chairman, Elijah Cummings, said impeachment was not ruled out.

“A lot of people keep asking about the question of impeachment ... We may very well come to that very soon, but right now let’s make sure we understand what Mueller was doing, understand what Barr was doing, and see the report in an unredacted form and all of the underlying documents,” he told MSNBC.

Short of attempting impeachment, Democratic lawmakers can use the details of Mueller’s report to fuel other inquiries already underway by congressional committees.

Only two U.S. presidents have been impeached: Bill Clinton on charges of perjury and obstruction of justice in 1998 and Andrew Johnson in 1868 after firing his secretary of war in the tumultuous aftermath of the American Civil War. Both were acquitted by the Senate and stayed in office.

In 1974, a House committee approved articles of impeachment against President Richard Nixon over the Watergate scandal but he resigned before the full House voted on impeachment.

(For a 'Link to Mueller report' click here)

(For a graphic on 'A closer look at Mueller report redactions' click tmsnrt.rs/2VSx7HZ)