Three moderate Democrat senators — Joe Manchin (WV), Doug Jones (AL), and Kyrsten Sinema (AZ) —may ultimately vote to acquit President Donald Trump in the upper chamber’s impeachment trial, according to a new report.

At least one of the senators have signaled that they could vote in favor of only one impeachment article — the abuse of power — but oppose obstruction of Congress.

In an interview with Politico this week, Manchin said he will only support one of the articles if he “can explain one and not the other.” The West Virginia Democrat, who has yet to decide on whether he will run for re-election in 2024, said he will only make a final decision on how he will vote only after the trial concludes.

“I know it’s hard to believe that. But I really am [undecided]. But I have not made a final decision. Every day, I hear something, I think ‘this is compelling, that’s compelling,’” he said. “Everyone’s struggling a little bit.”

Jones, the most vulnerable Senate incumbent on the Democrat side, has previously taken aim at the “obstruction of Congress” article and has said he is “troubled” that House Democrats failed to call White House officials as witnesses during their own proceedings.

“I don’t think I’ve totally decided. I certainly have [been] leaning one way or the other. That needle moves” Jones told Politico. “I am leaning in certain ways but I want to hear, I truly, honestly, want to hear the entire trial.”

When it comes to Sinema, the freshman senator who broke with Democrats to confirm Attorney General William Barr, her silence on impeachment suggests her vote remains up in the air. A spokesperson for the lawmaker recently said she supports gathering additional evidence to “make a more fully informed decision at the end of the trial.”

The senators’ remarks come as Democrats seek to call former White House National Security Advisor John Bolton as a witness. On Sunday, the New York Times reported that Bolton’s upcoming book alleges that President Trump wanted to tie U.S. military to Ukraine to inquiries into allegations of corruption against former Vice President and 2020 Democrat candidate Joe Biden, and his son, Hunter Biden. President Trump has denied the claims, calling them categorically “false” during an Oval Office meeting with Israeli Prime Minister Benjamin Netanyahu.

On Wednesday morning, President Trump took direct aim at Bolton in a pair of tweets, accusing him of penning a “nasty & untrue book” about his time in the White House.

“For a guy who couldn’t get approved for the Ambassador to the U.N. years ago, couldn’t get approved for anything since, ‘begged’ me for a non Senate approved job, which I gave him despite many saying ‘Don’t do it, sir,’ takes the job, mistakenly says ‘Libyan Model’ on T.V., and many more mistakes of judgement [sic], gets fired because frankly, if I listened to him, we would be in World War Six by now, and goes out and IMMEDIATELY writes a nasty & untrue book. All Classified National Security. Who would do this?” the president wrote.