WASHINGTON Its not going to be easy for Republicans to impeach President Joe Biden.

Impeaching Homeland Security Secretary Alejandro Mayorkas was supposed to be an appetizer before the main course, but the Mayorkas impeachment failed by a single vote on Tuesday.

It was an embarrassing setback for House Speaker Mike Johnson (R-La.) that foreshadowed the difficulty of a high-stakes presidential impeachment attempt.

The main obstacle is math: Republicans have such a slim majority that it only took three defections to tank the vote on Tuesday. Johnson can pad the margin somewhat by making sure to schedule the vote when fewer lawmakers are absent for medical reasons, resignations or expulsions .

But one of the Mayorkas defectors has already signaled skepticism about the case against Biden, which is based in part on bogus claims he twisted U.S. foreign policy as vice president in order to get a Ukrainian prosecutor fired.

Republicans in the House who are itching for an impeachment are relying on an imagined history, Rep. Ken Buck (R-Colo.) wrote in a Washington Post opinion article last year debunking the Ukrainian corruption claims.

Buck wound up voting to authorize the impeachment inquiry in December but has given no indication that his view of the corruption case has changed.

Republicans have been laying the groundwork for Bidens impeachment since last year, alleging he received the proceeds of his sons and brothers efforts to cash in on the family name. Republicans have sifted through thousands of pages of family bank records obtained through subpoenas, but so far theyve shown only that Hunter Biden paid his dad back for helping him buy a truck .