Sen. Ron Johnson scrambles after accidentally becoming fourth GOP senator to support Bolton testimony

Sen. Ron Johnson (R-WI) on Wednesday briefly became the fourth Republican senator to say that former National Security Adviser John Bolton should testify -- and then he changed his mind.

Democrats would need four Republican senators to vote with them in order to hear Bolton's testimony. Senators Lisa Murkowski (R-AK), Susan Collins (R-ME) and Mitt Romney (R-UT) are all on record wanting to hear Bolton's testimony.

And on Tuesday, Johnson suggested to reporter Adam Klasfeld that he was ready to hear Bolton's testimony. But the senator quickly walked back his remarks.