Donald Trump

Updated at 5:22 p.m. ET

Michael McKinley, a seasoned diplomat — and up until last week, a senior adviser to Secretary of State Mike Pompeo — has testified before House committees that are leading the impeachment inquiry into President Trump.

Updated at 8:30 p.m. ET

Congressional Democrats walked out of a bipartisan White House meeting with President Trump about his decision to pull U.S. troops out of Syria, a meeting in which Trump called House Speaker Nancy Pelosi "a third-rate politician" according to Senate Minority Leader Chuck Schumer.

Speaking to reporters on the White House driveway Wednesday after the meeting, Pelosi said the president had a "meltdown" inside, looked shaken, "and was not relating to reality."

The White House removed the core of its Ukraine policy team in the spring and replaced it with "three amigos" considered more reliable for the plan to pressure Kyiv, a senior U.S. diplomat was described as telling House investigators on Tuesday.

That's according to the account Rep. Gerry Connolly, D-Va., gave to reporters about the closed-door deposition by George Kent, the deputy assistant secretary in the State Department's European and Eurasian Bureau.

The fourth Democratic debate was a long one, about three hours, and ended after 11 p.m. ET.

You might not have made it through the whole thing, but there were some potentially consequential moments.

Here are six takeaways:

1. The scrutiny came for Warren, and her vulnerabilities were exposed some

Sen. Elizabeth Warren of Massachusetts was under fire Tuesday night from several opponents, and when that happens to a candidate, you know they're a front-runner.

Democrats onstage during their party's presidential debate were quick to condemn President Trump's abrupt and unilateral decision to withdraw U.S. forces from Syria. But their responses as to what role the U.S. should play in the region were generally cloudier.

Trump's decision last week appeared to set in motion a Turkish incursion into northern Syria and the advancement of Turkish-backed militias against Kurdish forces that had helped the United States battle ISIS.

Ukraine was bound to come up during Tuesday's Democratic presidential debate at some point, but when it did, it quickly became clear that neither former Vice President Joe Biden nor his primary opponents wanted to focus on it.

With the debate's second question, Biden was given a chance to address the unfounded allegations lobbed by President Trump: that Biden used his federal power to corruptly favor a Ukrainian gas company that was paying his son, Hunter.

Updated at 8:59 p.m. ET

The Trump administration is proposing to exempt Alaska's Tongass National Forest from long-standing protections against logging and development, opening the door for potential timber harvesting on 165,000 acres of old-growth forest.

Then-national security adviser John Bolton was distressed about Rudy Giuliani. Trump's personal lawyer had bypassed established procedure for representing the White House with a foreign leader and had launched a secret back channel of communication with Ukraine. The shadowy moves were so potentially combustible that Bolton in private meetings earlier this year called Giuliani "a hand grenade who is going to blow everybody up."

Ronan Farrow's 2017 exposé of the sexual misconduct allegations against film producer Harvey Weinstein in The New Yorker earned him a Pulitzer Prize and helped usher in the #MeToo movement. Now, in his new book, Catch and Kill, Farrow writes about the extreme tactics Weinstein allegedly used in an attempt to keep him from reporting the story.

In an interview with ABC News that aired Tuesday morning, Hunter Biden said his involvement in the board of Ukrainian gas company Burisma was, in retrospect, "poor judgment on my part," although he said he did "nothing wrong at all." Biden asked, "was it poor judgment to be in the middle of something that is ... a swamp in many ways? Yeah."

Biden also reiterated that he will not work for any foreign companies should his father become president.