Impeachment is set to end Wednesday. As senators make their speeches before the final vote, the only real uncertainty is whether a couple of moderate Democrats will vote to acquit President Donald Trump along with most or all Republicans.

But the resistance will continue, according to Jerry Nadler (D-N.Y.), impeachment manager and House Judiciary Committee chairman.

CNN's Manu Raju asked Nadler about the party's next moves after the impeachment trial ends, and Nadler responded that it is "likely" that Democrats will subpoena former national security adviser John Bolton and continue investigating the president even after he is acquitted.

"First of all, I think when you have a lawless president, you have to bring that to the fore and you have to spotlight that. You have to protect the Constitution, whatever the political consequences. Second of all, no, as more and more lawlessness comes out, I presume the public will understand that," Nadler said.

House Democrats declined to fully pursue Bolton's testimony during the impeachment inquiry due to the prospect of a lengthy legal battle, despite clear indications from other witnesses that Bolton was one of three or four primary officials who had full knowledge of Ukraine dealings and direct contact with the president on the subject.

So, instead of testifying under oath, Bolton is attempting to publish a book in which he reportedly affirms the Democratic allegation that Trump wanted to withhold military aid to Ukraine until President Volodymyr Zelensky agreed to announce or open an investigation into former Vice President Joe Biden and his son, Hunter Biden.

Bolton said he would testify before the Senate if he were subpoenaed, but the Senate voted against hearing from new witnesses during the trial.

So, as impeachment goes the way of the Robert Mueller report, Democrats will continue to pursue accusations of corruption by President Trump, even as the election approaches. And, if he is re-elected in November, four more years of Trump may yield four more years of House investigations — unless Republicans regain the majority.