Republicans Tuesday laid out their impeachment strategy, circulating an 18-page memo telling lawmakers to say President Trump did nothing wrong.

The memo came on the eve of the public phase of the House impeachment inquiry, with testimony set for Wednesday from veteran diplomat Bill Taylor who said in a closed-door deposition it was clear to him Trump was withholding military aid and a White House visit from Ukraine to pressure Kyiv into investigating his political rivals.

“The body of evidence to date does not support the Democrat allegations that President Trump covered up misconduct or obstructed justice,” the memo states. Instead, it asserts, the president was doing what “Americans elected him to do.”

Republicans are expected to defend Trump’s actions as innocent, characterizing them as an honest attempt to deal with corruption in the former Soviet republic, which is under pressure from Russia-backed separatists in its eastern provinces.

The Republicans plan to cast the impeachment proceedings as an attempt by government insiders to impeach the president simply because they disagreed with him. They say Trump’s action was “entirely reasonable.”

In a July 25 phone call at the heart of the investigation, Trump asked Ukraine President Volodymyr Zelensky to do him a “favor” and investigate former Vice President Joe Biden and his son, Hunter, who was a director on the board of Ukraine energy company Burisma. He also asked for an investigation of a conspiracy theory linking Ukraine to 2016 presidential election interference rather than Russia. On Tuesday, Trump pledged to release the transcript of a second call with Zelensky “before the end of the week.”

Biden addressed the controversy during a CNN town hall, saying there is absolutely no indication of wrongdoing on his part, and if Trump really was interested in routing corruption, he would release his tax returns. Trump is the only modern presidential candidate who has not revealed his returns.

Republican staff of the three committees involved in the impeachment inquiry distributed copies of the party strategy late Monday. The document says Republicans should cast doubt on witnesses.

“Democrats want to impeach President Trump because unelected and anonymous bureaucrats disagreed with the president’s decisions and were discomforted by his telephone call with President Zelensky,” the memo says. “The president works for the American people. And President Trump is doing what Americans elected him to do.”

Elsewhere, acting White House Chief of Staff Mick Mulvaney said he would not file a petition to block a House subpoena. Instead, he said he would follow Trump’s directive against cooperating with the investigation. Mulvaney had been scheduled for a closed-door deposition last week but failed to appear.

House Intelligence Committee Chairman Adam Schiff, D-Calif., who is leading the impeachment investigation, warned the GOP against outing the whistleblower, whose complaint about the July 25 call sparked the impeachment process, saying releasing the name would violate congressional ethics rules.

House Republicans want the whistleblower to testify, but Democrats say that’s not necessary because other witnesses already have corroborated his allegations.

In addition to Taylor, lawmakers will hear Wednesday from Deputy Assistant Secretary of State George Kent. Former Ukraine Ambassador Marie Yovanovich, who was ousted from her post as a result of a smear campaign orchestrated by Trump attorney Rudy Giuliani, is scheduled to testify Friday.