US President Donald Trump shakes hands with Speaker of the House Nancy Pelosi as he departs following the Friends of Ireland Luncheon in honor of Irish Prime Minister Leo Varadkar at the US Capitol in Washington, DC, March 14, 2019.

President Donald Trump has reason to celebrate the Mueller report's core conclusions. Given facts previously disclosed, they were as good as he could have hoped for.

That doesn't make those conclusions, as a measure of Trump's conduct, good. The brief summary released by Attorney General William Barr shows Mueller found evidence the president sought to obstruct justice in the investigation of Russian interference on his behalf in the 2016 election, if not enough to prosecute him.

More significantly, Barr's summary does not address why Trump and numerous associates, during and after the campaign, sought to conceal their interactions with various Russian actors — about a Moscow real estate project, an offer of dirt on Hillary Clinton, economic sanctions imposed by President Barack Obama. It does not address Trump's willingness to accept Vladimir Putin's word over that of U.S. intelligence agencies, and his no-aides-present talks with the Russian leader.

Those omissions relate to the counterintelligence portion of the probe Mueller inherited as special counsel after Trump fired FBI Director James Comey. Beyond prosecutable crimes, counterintelligence investigators look for whether their subject has been compromised by a foreign power to the detriment of U.S. national security. If Mueller reached conclusions about that regarding Trump and Russia, he has not disclosed them.

Nor is Trump clear of legal jeopardy. He has been implicated, though not charged, in campaign finance felonies to which his former lawyer Michael Cohen has pleaded guilty.

City, state and federal prosecutors in New York continue investigating his business, charitable foundation and inauguration. In addition to Cohen, Trump's former campaign manager, deputy campaign manager and national security adviser, among others, have confessed to crimes.

Yet few legal analysts have expected the president to be prosecuted on any criminal charges during his term. The Justice Department has for decades accepted that, as a matter of constitutional law, he could not be.

Thus the real significance of Mueller's conclusions lies in the realm of politics. Trump and his GOP allies in Congress have avoided their worst-case scenarios.

Trump has repeatedly and emphatically insisted that his campaign did not collude with Russia in 2016. The failure of Mueller — a dogged investigator of impeccable integrity — to legally establish otherwise provides powerful backup for his claim.

That in turn reassures GOP lawmakers that they can justify continued backing for a president who remains overwhelmingly popular among rank-and-file Republicans, if not the broader public. The prospect of bipartisan cooperation on any stage of an impeachment process has become vanishingly small.

Congressional Democrats immediately complained about how Barr translated Mueller's conclusions into the four-page letter released publicly over the weekend. While noting that the special counsel "does not exonerate" Trump of obstruction of justice, Barr declared himself that no prosecutable case exists even if the Justice Department believed it could indict a sitting president.

But if they believe otherwise, Democrats still have the ability to act using the power they won last November when they recaptured the House. They have initiated multiple investigations of Trump's finances and his use of power.

Democrats soon will obtain and make public the Mueller report itself, absent whatever the Justice Department deems classified on legal or national security grounds. They can summon Barr to press him on his classification decisions and his legal reasoning on obstruction.

They can mine evidence the special counsel gathered on Trump's 2016 actions beyond the confines of cooperation with "the Russian government" that Barr noted in his public summary. They can summon Mueller to explain his interpretation of the evidence.

The absence of bipartisan support heightens the risk of attempting to impeach Trump. But that option remains open for Democrats to pursue if they consider it justified.

House Speaker Nancy Pelosi vows Democrats will neither pursue nor avoid that step for political reasons. As the 2020 campaign for the White House and Congress accelerates, her commitment to decide the impeachment question without regard to politics now faces a test.