Yes, there are two ways of looking at it.
Rush is an unapologetic conservative. Carville makes his liberal point-of-view illegitimate by sucking up to Rush by going to his wedding.
Not necessarily.
His wife, Mary Matalin, is a good friend of Rush. She worked for Bush 41.
Sometimes, people can put politics aside. Like when I visit my sister.
Carville was probably just doing what most smart husbands do - going along with what the wife wants.