The question before Congress is: Did President Trump commit an impeachable offense when he allegedly pursued a politically charged quid pro quo? He is accused of withholding U.S. military aid and a White House visit from Ukraine unless its president announced two investigations: one into Burisma, a Ukrainian company that employed the son of Mr. Trump's 2020 rival, Joe Biden, and another into unfounded claims that Ukraine interfered in the 2016 election to help Mr. Trump's opponent, Hillary Clinton.

Here are the highlights from the impeachment inquiry this week — followed by analysis:

What the legal experts said

The impeachment process moved to the House Judiciary Committee this week. On Wednesday, it held a hearing with four constitutional law professors. Three of them said that given the evidence and constitutional precedent, Mr. Trump should be impeached. But one of the witnesses, Jonathan Turley, a CBS News legal analyst, said more evidence would be required, specifically from the officials with direct knowledge of the delay in military aid, including acting White House chief of staff Mick Mulvaney, who is following White House orders to not testify. 

On the question of whether Mr. Trump committed bribery, the same three experts were in unison, while Turley was the lone dissenter. All four agreed, however, that the Constitution allows for a president to be impeached even if he didn't break a law. 

White House refuses to participate

Despite Mr. Trump's complaints that the impeachment process hasn't involved him or anyone to represent him directly, the White House declined the Judiciary Committee's invitation to participate in Wednesday's hearing or any future House hearing. Chairman Jerry Nadler expressed disappointment but said "if the President has no good response to the allegations, then he would not want to appear before the Committee. Having declined this opportunity, he cannot claim that the process is unfair. "

A new Senate strategy

The White House has ordered current and former Trump officials not to testify in the impeachment inquiry and frequently refers to the process as a "one-sided sham." But the president appears to have a different attitude about impeachment if it reaches the Senate, where, unlike the House, Republicans are the majority party. Mr. Trump said this week that he would "love" for several of the highest-profile officials he blocked from testifying in the Democratic-dominated House — Secretary of State Mike Pompeo, Mulvaney and former Energy Secretary Rick Perry — to testify in the Senate. 

After House Speaker Nancy Pelosi called for Democratic committee chairs to start drafting the articles of impeachment, Mr. Trump said, "if you are going to impeach me, do it now, fast, so we can have a fair trial in the Senate, and so that our Country can get back to business."

Dueling reports

Democrats on the House Intelligence, Foreign Affairs and Oversight Committees released a report that outlines their conclusions from weeks of public and private testimony they heard from current and former Trump officials. The report details nine key findings and concludes that "the evidence of the president's misconduct is overwhelming, and so too is the evidence of his obstruction of Congress." Here's a snippet of the 300-page report:

• Mr. Trump "ordered the suspension of $391 million in vital military assistance" to Ukraine "without any legitimate foreign policy, national security, or anti-corruption justification."
• The president "solicited the interference of a foreign government, Ukraine, in the 2020 U.S. presidential election" and "sought to undermine the integrity of the U.S. presidential election process."
• He "sought to pressure and induce Ukraine's newly-elected president, Volodymyr Zelensky, to publicly announce unfounded investigations" that could benefit his 2020 reelection campaign. 

The Republicans on the Intelligence Committee refused to endorse the report. In fact, before Wednesday's hearing, the Republicans on the impeachment committees released their own report defending the president's actions. Their report contradicted the testimony of some current or former diplomats and claimed that Ukraine meddled in the 2016 U.S. election to help Clinton — a theory that the former top national security adviser on Russia called "a fictional narrative that has been perpetrated and propagated by the Russian security services themselves."

Congressional conflicts

New phone records show Congressman Devin Nunes, the top Republican on the House Intelligence Committee and a vociferous opponent of the impeachment inquiry, spoke in April with Mr. Trump's personal attorney Rudy Giuliani and Lev Parnas, a Giuliani associate who was recently indicted for campaign fraud. Parnas said the Democrats' report corroborates his account. Parnas was reportedly willing to tell Congress about meetings that Nunes supposedly had last year with a former Ukrainian prosecutor to discuss an investigation into Joe Biden. Nunes denied the meetings ever happened.

Long-term impeachment impact 

If the president isn't impeached, the three constitutional law experts called by Democrats this week believe that would set a dangerous precedent. University of North Carolina's Michael Gerhardt warned that if Mr. Trump's conduct "is not impeachable, then nothing is impeachable." Pamela Karlan, a professor and co-director of the Supreme Court Litigation Clinic at Stanford Law School, said "it's not a real democracy, it's not a mature democracy, if the party in power uses its power to go after its enemies."

The House Democrats' report echoed a similar sentiment: "The damage to our checks and balances, and to the balance of power within our three branches of government, will be long-lasting and potentially irrevocable if the president's ability to stonewall Congress goes unchecked." 

But Turley, the Republicans' expert witness, cautioned the Democrats about the need for the public's support. "If you rush this impeachment, you're going to leave half the country behind." 

Meanwhile, Mr. Trump predicted that the impeachment, which he calls a "hoax," will be a "boon" to Republicans and a harm to Democrats in the 2020 election. 

Up next week

The Judiciary Committee will hold its next meeting on Monday, featuring presentations from Democratic and Republican legal counsels for the Intelligence and Judiciary Committees.

— Stefan Becket, Melissa Quinn, Grace Segers and Kathryn Watson contributed reporting.

Perspective

A land of absolutes. That appears to be where impeachment is now and cannot help but plunge deeper into. 

In a season of acceptance, reflection, hope and possibility, the season of impeachment looks and feels more like a place where possibility retreats, hope evaporates, anger pulverizes reflection and inflexibility reigns.

House Speaker Nancy Pelosi said this week that President Trump "gave us no choice" but to draft the articles of impeachment. Trump said again he "did nothing wrong." Impeachment, therefore, falls into a nether world of absolutes — perfect guilt and perfect innocence.

Certainly nothing in politics is perfect. But absolutes define the process so far as each side bathes itself in unrivaled legitimacy.

"It is about the Constitution of the United States, the oath of office we take to protect and defend the Constitution from all enemies — foreign and domestic," Pelosi said. "It is about the president not honoring his oath of office. This has absolutely nothing to do with politics. It isn't about politics, partisanship, Democrats and Republicans — that is totally insignificant."

When the White House rejected a second House Judiciary Committee offer to participate in impeachment hearings, the president's legal counsel, Pat Cipollone, wrote that the inquiry "is completely baseless and has violated basic principles of due process and fundamental fairness," adding "adopting articles of impeachment would be a reckless abuse of power by House Democrats, and would constitute the most unjust, highly partisan, and unconstitutional attempt at impeachment in our Nation's history."

In the Senate, Democratic Leader Charles Schumer said the House proceedings were "deliberate, evenhanded and serious." But the Senate majority leader, Mitch McConnell, called impeachment "performance art for coastal elites."

The land of absolutes was also visible in the hearing on constitutional grounds for impeachment. One scholar, Michael Gerhardt of the University of North Carolina, proclaimed that if Trump's alleged offenses in the Ukraine matter were not impeachable, "nothing is impeachable." Meanwhile, Jonathan Turley, a CBS News contributor and law professor at George Washington University, said if Democrats seek to impeach Trump for failing to turn over documents — while not waiting for a court ruling on whether that is legal — this would constitute an "abuse of power."

Even when law professors spoke of the plainly nonpartisan Constitution, questions from Democrats were directed primarily at professors with whom they agreed while Republicans' questions flowed to their one requested witness and impeachment skeptic, Turley. 

In sum, in the partisan climate of absolutes, even the Constitution was not given the courtesy of a robust exchange of opinions about what it says, what it meant and how the nation should apply it to the available evidence.

Thank goodness absolutism did not prevail at the Constitution's drafting.

— Major Garrett