In his final statement on the report that has sparked controversy for two years, U.S. Special Counsel Robert Mueller Wednesday signaled the possibility that President Donald Trump committed a crime, but stopped short of saying it definitively.

If we had "confidence that the president clearly did not commit a crime, we would have said so," Mueller said at a press conference. Mueller added that he found "insufficient evidence to charge a broader conspiracy" on whether there was interference in the election, and announced that he would step down.

Mueller's statements seemed to indicate he suspected wrongdoing but could not prove it, prompting some key Democrats to ratchet up calls to impeach Trump.

"The next step is for the House Judiciary Committee to open an impeachment inquiry to formally begin consideration of whether or not articles of impeachment should be filed," said David Cicilline, a member of the Judiciary panel.

"The opening of this inquiry will allow the committee to collect evidence, compel the attendance of witnesses, and decide how to proceed."

The Mueller investigation -- which sought to find evidence that the Trump campaign colluded with Russia to clinch the 2016 elections -- took nearly two years and was concluded several months ago without finding a smoking gun.

Democrats, however, are still convinced that Trump committed a crime, and continue to investigate.

House Judiciary Chairman Jerrold Nadler said the Muller report "found substantial evidence that Russia attacked our political system and that the president sought to obstruct Mueller's investigation over and over again.

"He said that the "Constitution points to Congress to take action to hold the president accountable," signaling that Democrats may consider impeachment, although falling short of actually calling for such proceedings to begin."

Given that Special Counsel Mueller was unable to pursue criminal charges against the president, it falls to Congress to respond to the crimes, lies and other wrongdoing of President Trump -- and we will do so," Nadler added.

In response, White House Press Secretary Sarah Sanders told reporters Wednesday that Team Trump is "always prepared" for an impeachment fight, "but I don't think the American people deserve that."

"Every single minute that Congress spends on that, we're not spending on infrastructure," or myriad other domestic and international issues that demand White House attention, she said.

"Every single thing that they are doing is taking away from things that could help the American people," she added.

Though calls for impeachment are heightened, analysts said an impeachment could well galvanize Trump's base and tamp up support for him like never before, and could thus cause the impeachment to backfire.

"I think Democrats will be cautious about impeachment because they know it will mobilize the Republican base and help Trump in the 2020 elections," Brookings Institution Senior Fellow Darrell West told Xinhua.

Trump's supporters view the Mueller report as a political witch hunt, and identify Trump as an anti-establishment figure who is fighting for them while Washington elites try to derail him.

Christopher Galdieri, assistant professor at Saint Anselm College, told Xinhua it's clear that Mueller believes Trump "committed acts that obstructed justice."

"But Mueller feels bound by the (U.S. Department of Justice) policy that a sitting president cannot be indicted," Galdieri said.

Republican Strategist and TV news personality Ford O'Connell told Xinhua: "We didn't hear anything that wasn't in the report and contrary to the fanfare in the media, Mueller didn't say Trump was guilty of anything."

"In our legal system you are innocent until proven guilty," he added, noting that hard proof and facts are required in the U.S. rule-of-law system.

"What he's done here is to throw Democrats a political bone," O'Connell said of Mueller.

Dan Mahaffee, senior vice president and director of policy at the Center for the Study of the Presidency and Congress, told Xinhua: "Mueller's comments are clear in the sense that the Mueller Report is the final statement on what he can say about the investigation, and he made a direct statement that it is now Congress's sole responsibility to further investigate the president."

"The report can no longer be considered an exoneration, as Mueller specifically ruled that out," Mahaffee said.

Xinhua