President Trump has been acquitted, but now Democrats — and Republicans — are seriously considering returning to battle over Ukraine with new waves of document and witness subpoenas.

What we're hearing: Many House Democrats want to pick up where the White House stonewalled them during impeachment. That could include renewed moves to seek John Bolton's testimony if he doesn't go public soon, while several Senate Republicans are contemplating investigations of Burisma, the Bidens and more.

The bitter debate over whether Trump's actions toward Ukraine were justified isn't dying with the end of the impeachment trial, and both parties see the opportunity to use these investigations to bring new evidence to light that could motivate voters ahead of the November elections.

What they're saying: Several Democrats want to continue investigating Trump and Ukraine and are still considering subpoenaing everyone from Lev Parnas to top current and former White House aides, especially if the White House blocks publication of former national security advisor Bolton's forthcoming book.

"John Bolton has to speak; the country wants to hear him," said Rep. Jamie Raskin (D-Md.). "We can't run away from our oversight duties."

House Judiciary Chairman Jerry Nadler (D-N.Y.) told CNN Wednesday that House Democrats will “likely” subpoena Bolton and continue investigations.

"The general public deserves to know the facts of what happened here. And if the president tries to tie up Bolton’s book indefinitely, what he's depriving the voting public of is the insight that I would hope my Republican colleagues would agree they deserve," Sen. Chris Coons (D-Del.) told Axios.

Lead House impeachment manager Adam Schiff (D-Calif.), speaking in the Senate trial on Jan. 31, said that “the facts will come out in the end. In all of their horror, they will come out."

"There are more court documents and deadlines under the Freedom of Information Act," Schiff said. "Witnesses will tell their stories in future congressional hearings, in books and in the media. The documents the president is hiding will come out. The witnesses the president is concealing will tell their stories.”

Some Republicans are just as hungry for Biden blood.

Immediately after Trump's acquittal Sens. Chuck Grassley (R-Iowa) and Ron Johnson (R-Wis.) announced a review of "potential conflicts of interest posed by the business activities of Hunter Biden and his associates during the Obama administration."

On Sunday, Sen. Lindsey Graham (R-S.C.) told Fox Business' Maria Bartiromo that, as Chairman of the Senate Judiciary Committee, he would investigate the Bidens and whether their dealings with Ukraine were corrupt: “You should expect us to do this. If we don’t do it, we’re letting you down," he said.

Sen. Ted Cruz (R-Texas) said: “I think there needs to be an investigation" but that "it's important to note it's not it's not Hunter Biden, who needs to be investigated. It is rather Joe Biden." Cruz said, "I'd like to see the Judiciary Committee investigate. I'd like to see Foreign Relations investigate. I'd like to see the Department of Justice investigate."

Other Hill Republicans tell Axios there's little appetite to truly go after the Bidens now that Trump has been acquitted.

GOP aides tell Axios Trump's fiercest allies may do something to feed the narrative, but it'll be "extraordinarily half-assed and slow-walked," as one aide put it.

Some Republicans fear aggressively pursuing any investigations about Burisma will give the appearance of trying to hurt Joe Biden — a former Senate colleague —politically, which isn't worth it to them, the aide said, "especially since the Biden campaign looks like it’s toast."

"The issue of how Ukraine is progressing on corruption is a legitimate one, especially if it's a country that we intend to continue to support with aid," Sen. Marco Rubio (R-Fla.) said. While questions about Burisma are "legitimate," he said, "I’m just not sure at this stage that Congress is the appropriate place."

Go deeper: The daily highlights from Trump's Senate impeachment trial