Wrong.
The right to due process as codified in the 4th, 5th, and 6th Amendments concerns solely government action where a citizen is in jeopardy of losing his life, liberty, or property through criminal prosecution or civil action – none of which applies to Santos.
Santos doesn’t ‘own’ a seat in Congress, he’s not at risk of imprisonment or loss of personal property. The House expulsion process is neither a judicial proceeding nor a criminal prosecution.
Consequently, there is no ‘entitlement’ to due process, no rights of Santos have been violated.