Republicans appear to be scared of Rep. Marjorie Taylor Greene (R-GA), a former aide to two House Speakers told MSNBC Tuesday — but they shouldn’t be. Brendan Buck served under Speakers Paul Ryan and John Boehner, and witnessed each dealing with the far-right flank of the party attempting to top the party leadership. Now that Greene is threatening to vacate the speaker’s chair, Buck is urging members of the party not to fear her. “It might literally be just that simple,” Buck said as he spoke about Republicans standing up to Greene. Want more breaking political news? Click for the latest headl…