Lindsey Graham abruptly cancels planned press conference in wake of John Bolton bombshell

Sen. Lindsey Graham (R-SC) abruptly canceled a planned press conference that had been scheduled for Monday morning after a bombshell report claimed that former national security adviser John Bolton is backing up a key allegation in the impeachment case against President Donald Trump.

Graham was originally set to talk at 11:30 a.m. on Monday alongside several of his fellow Republican senators, but Politico's Jake Sherman reveals that press event has now been shut down.

Earlier in the morning, Graham floated a potential willingness to call Bolton to testify, although he qualified this by saying that Trump should also get to request any witnesses he wanted as well.

"If there is a desire and decision by the Senate to call Democratic witnesses, then at a minimum the Senate should allow President Trump to call all relevant witnesses he has requested," the senator wrote on Twitter.

Revelations about Bolton claiming that the president directly tied security aid to Ukraine to investigating former Vice President Joe Biden has rocked Capitol Hill this week and has at least temporarily thrown GOP efforts to quickly acquit Trump without calling witnesses into turmoil.