I read the unnamed congressman is likely Pete Sessions. This article from a few days ago gives some background. This scandal keeps netting more and more people.
Congressman Scored Millions After Targeting Ukraine Diplo
Pro-Trump group America First appears to have pushed the legal limits with a seven-figure ad campaign on behalf of Pete Sessions.www.thedailybeast.com
Saw that too. And he's not the only one getting that fat corrupt Ukrainian dough.
(See thread. McCarthy himself is in the post linked but others too.)