(Reuters) - The U.S. House of Representatives Judiciary Committee, one of the most argumentative panels in Congress, is set to begin weighing formal impeachment charges against President Donald Trump over his dealings with Ukraine.

FILE PHOTO: Chairman Jerrold Nadler (D-NY) and ranking member Doug Collins (R-GA) are seen as former Trump campaign manager Corey Lewandowski testifies before a House Judiciary Committee during a hearing on "Presidential Obstruction of Justice and Abuse of Power," in the Rayburn House Office Building on Capitol Hill in Washington, U.S., September 17, 2019. REUTERS/Sarah Silbiger/File Photo

Packed with Democratic progressives and Republican conservatives known for not pulling their verbal punches, the panel’s proceedings could quickly become unruly.

Following are members of the Democratic-led panel who may play a prominent role in proceedings that start on Wednesday with testimony from legal experts on what constitutes an impeachable offense under the U.S. Constitution.

DEMOCRATS:

Chairman Jerrold Nadler

Nadler, 72, is a hard-nosed New York City attorney who has long been a Trump antagonist. Decades ago, as a state assemblyman, Nadler opposed a Trump real estate development in his district on Manhattan’s West Side.

As committee chairman, Nadler launched a broad corruption probe into Trump’s presidency that centered on U.S. Special Counsel Robert Mueller’s report on Russian interference in the 2016 U.S. presidential election. That probe was sidelined in September, when the impeachment focus shifted to an inquiry into Trump’s dealings with Ukraine, led by House Intelligence Committee Chairman Adam Schiff.

Now, Nadler returns to the spotlight to consider recommending possible articles of impeachment against Trump.

Representative Steve Cohen

Cohen, 70, who chairs the House Judiciary Subcommittee on the Constitution, Civil Rights and Civil Liberties, announced his intention to bring articles of impeachment against Trump in August 2017, after the president said there were “very fine people” on both sides of a white nationalist rally in Charlottesville, Virginia, where a woman was killed. Three months later, he introduced an impeachment resolution that went nowhere in the then-Republican-controlled chamber.

A Tennessee Democrat, Cohen also drew media attention earlier this year by eating fried chicken in the Judiciary hearing room to mock Attorney General William Barr’s decision not to show up and answer questions.

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Representative Hank Johnson:

Johnson, 65, a Georgia Democrat, drew criticism in January by comparing Trump to Adolf Hitler in a speech in Atlanta, describing both men as nationalists known to use incendiary rhetoric to inflame racial and ethnic divisions.

An African-American, Johnson later defended his comments, saying it was a necessary comparison that black Americans especially could not afford to ignore.

Johnson chairs the House Judiciary Subcommittee on Courts, Intellectual Property and the Internet.

REPUBLICANS:

Ranking Committee member Doug Collins

The 53-year-old Georgia Republican, a key Trump ally, is likely to lead a forceful defense of Trump in upcoming proceedings. Collins has denounced the Democratic-led impeachment inquiry as a “sham” and says he wants Schiff to testify before the Judiciary panel.

Collins is also reported to be Trump’s pick to fill the U.S. Senate seat that fellow Georgia Republican Johnny Isakson will vacate at year end. But state Governor Brian Kemp is expected to appoint another candidate, businesswoman Kelly Loeffler, to the post.

Representative Jim Jordan

A Trump favorite on Capitol Hill, the pugnacious Ohio Republican has been one of the president’s biggest and most forceful defenders throughout the inquiry. Republican leaders even gave the former college wrestler a temporary seat on the Intelligence Committee, from which to grill witnesses and assert the claim that no wrongdoing occurred in Trump’s dealings with Ukraine.

Now, the 55-year-old will try to use his combative style to upend Democrats as they propel their inquiry toward what is widely expected to be an impeachment vote by the full House before Christmas.

Representative Andy Biggs

Biggs, an Arizona Republican and chairman of the conservative House Freedom Caucus who has long been an ardent Trump defender, described the Judiciary Committee as “a bunch of brawlers sometimes” and predicted feisty proceedings in a recent Fox News interview.

He called for the resignation of U.S. Special Counsel Robert Mueller, who led the federal probe into Russian interference in the 2016 presidential election, and described Mueller’s findings as an “illegitimate attack” on Trump and the executive branch.

Representative Matt Gaetz

Gaetz figured prominently in the storming by Republican lawmakers of a secure congressional hearing room where the House Intelligence Committee heard closed-door testimony from impeachment witnesses in the probe’s initial weeks.

The 37-year-old Florida Republican also drew headlines on the eve of former Trump attorney Michael Cohen’s testimony earlier this year, by asking Cohen in a tweet if his wife knew about his “girlfriends.” The congressman also wondered whether Cohen’s wife would remain faithful while he was in prison. Gaetz later deleted the tweet and apologized after accusations of witness tampering.