Smells of desperation on these GOP Representatives' part. Muller is not going to be "rund oft" ( i.e. Oh Brother Where Art Thou) by a bunch of "Hogwallers". 
Had Manafort and Gates not appeared to have laundered millions of dollars and had Papadopoulos not lied to the FBI they wouldn't be in trouble.
As an Independent, I want Muller to follow this wherever it leads. I do not have the facts Mr. Muller has so I will defer to his experience and judgement as to which if any laws were broken and by whom.