They aren't concerned about Comey's testimony because they're pretty sure that none of their 'loyal constituents' (i.e. the Republicans residing in their districts) are going to be calling them and screaming 'impeachment!!' and they don't give a rat's ass about the rest of us. Trust me, I reside in a Republican district and our Congressman's office has made it pretty clear that our opinions don't count. They know that the Trumpettes will swallow Trump's inevitable tweets about 'Comey lies', 'fake news', 'Comey is sour grapes', 'no proof, I never said it'.