WASHINGTON (Reuters) - U.S. Democrats launch the public phase of their impeachment inquiry into President Donald Trump next week, with open, televised hearings set for Wednesday and Friday in the House of Representatives.

The committee room in the Longworth House Office Building where the first public hearings in the impeachment inquiry against U.S. President Donald Trump are scheduled to take place is shown on Capitol Hill in Washington, U.S., November 6, 2019. REUTERS/Joshua Roberts

Since launching their inquiry on Sept. 24 into allegations that Trump abused his office for personal political gain, lawmakers in the Democratic-run House of Representatives have been holding hearings with current and former officials behind closed doors. Now they want to take their case for impeachment to the American public.

Here is what to expect from the hearings.

WHY ARE DEMOCRATS HOLDING THESE HEARINGS?

Democrats want to build a strong public case that Trump abused his presidential powers by pressuring Ukraine to launch corruption investigations involving the son of Joe Biden, the former vice president who is vying to be the Democratic nominee to run against Trump in the 2020 presidential elections. Democrats want the broadest possible public support should they choose to formally impeach Trump, which could happen by December. Any trial would take place in the Senate, which is controlled by Trump’s Republican Party.

Televised hearings will “be an opportunity for the American people to evaluate the witnesses for themselves,” House Intelligence Committee chairman Adam Schiff said.

In the hearings, the Democrats want to present evidence that Trump’s officials delayed security aid to Kiev and, with the help of Trump’s personal lawyer, Rudy Giuliani, used the lure of a possible White House meeting with Ukrainian President Volodymyr Zelenskiy to try to get Ukrainian compliance with Trump’s demands.

Trump has denied doing anything wrong.

HOW DO DEMOCRATS PLAN TO MAKE THEIR CASE?

Democrats have invited three diplomats who have previously testified behind closed doors to recount what they knew or heard about Trump and Giuliani’s dealings with Ukraine. These witnesses will be questioned by committee staff attorneys as well as lawmakers including Schiff and the senior Republican on the committee, Devin Nunes.

The Democrats will ask the diplomats to discuss their understanding of events before and after a July 25 phone call between Trump and Zelenskiy. According to a rough White House transcript of that call, the president pressed Zelenskiy to investigate a discredited conspiracy theory involving the 2016 election about a Democratic Party computer server, as well as a Ukrainian energy company in which Hunter Biden had been a board member.

Democrats are also expected to try to use the hearings to show that Trump obstructed justice - the basis of another possible article of impeachment - by detailing how he has blocked some witnesses from appearing and otherwise refused to cooperate with their probe. The White House has called the inquiry partisan and illegitimate as a basis for not cooperating.

Trump has complained bitterly on Twitter that the process does not allow him to be represented in the intelligence committee. “I get NO LAWYER & NO DUE PROCESS,” he wrote in one tweet.

However, Trump and/or his lawyer would be allowed to attend later hearings before the House judiciary committee, which will debate what, if any, articles of impeachment should be filed and sent to the floor for a vote.

WHO ARE THE WITNESSES?

The top U.S. diplomat in Ukraine, William Taylor, is considered a critical witness to the case against Trump. Taylor was upset to find out that security aid to Ukraine, as well as a White House meeting between Trump and Zelenskiy, had been delayed for political reasons.

“It’s crazy to withhold security assistance for help with a political campaign,” Taylor wrote earlier this year in a text message released by House investigators.

Another senior U.S. diplomat, George Kent, will appear with Taylor at Wednesday’s hearing. Kent said in closed-door testimony that he had been alarmed by efforts by Giuliani and others to pressure Ukraine to accede to Trump’s demands.

Former U.S. ambassador to Ukraine Marie Yovanovitch will testify on Friday. She says she was ousted from her post after she came under attack by Giuliani. She says Giuliani’s associates “may well have believed that their personal financial ambitions were stymied by our anti-corruption policy in Ukraine.”

The Democrats also could announce additional witnesses they expect to call to testify.

Republicans intend to request their own witnesses, possibly including the whistleblower, the U.S. official whose complaint about Trump’s dealings with Ukraine touched off the impeachment inquiry. Democrats can veto the Republicans’ witnesses.

HOW DO REPUBLICANS PLAN TO RESPOND?

Republicans have painted the Democratic-led inquiry as a partisan exercise and will seek to provide a different narrative for the millions of Americans expected to watch the hearings, while attempting to cast doubt on witness testimony.

They said on Friday Representative Jim Jordan, one of Trump’s most aggressive and tenacious defenders, would move to the intelligence committee for the public hearings phase of the inquiry.

Republicans may also follow the lead of Republican Representative Michael Turner, a member of the intelligence committee who said in September that Trump’s telephone conversation with Zelenskiy was “not ok,” but impeachment would be an “assault” on the electorate.

Republicans are already attacking the Democratic witnesses, saying that Yovanovitch’s recall as ambassador was a side issue, and that other witnesses’ knowledge of key events was largely third-hand.

“He (William Taylor) is admitting that he had no first-hand or second-hand knowledge of any of the developments,” a Republican party official told Reuters. “Yet Democrats are presenting him as their star witness for this whole endeavor to impeach the president.”

Republicans can also be expected to argue that Ukrainian officials did not feel pressured because they did not even know the $391 million in security aid had been held up at the time Trump asked them last July for a “favor.” They have also emphasized that the Ukrainians never announced the investigations Trump wanted, and that Zelenskiy said he did not feel “pushed” by Trump.