Even if the votes leading to it might not be secret, perhaps there’s a way to get to removal.
it’s not hard to imagine three senators supporting a secret ballot.
(A)ccording to current Senate procedure, McConnell will still need a simple majority—51 of the 53 Senate Republicans—to support any resolution outlining rules governing the trial. That means that if only three Republican senators were to break from the caucus, they could block any rule they didn’t like. (Vice President Mike Pence can’t break ties in impeachment matters.) Those three senators, in turn, could demand a secret ballot and condition their approval of the rest of the rules on getting one.
Some might say transparency in congressional deliberations and votes is inviolable, and it’s true that none of the previous Senate impeachments have been conducted via secret ballot. But the Senate’s role in an impeachment is analogous to a U.S. jury, where secret ballots are often used. When Electoral College gridlock has resulted in the House picking the president—the House elected Thomas Jefferson in 1800 and John Quincy Adams in 1824—that vote has been secret. And, of course, when citizens vote for president, they do so in private.[…]
A secret ballot might get Trump out of office sooner than everyone expects: The sooner any three Republican senators make clear that they will support nothing short of a secret ballot, the sooner Trump realizes his best course could be to cut a deal, trading his office for a get-out-of-jail-free card—a clean slate from prosecutors—just as Vice President Spiro Agnew did.