https://www.opensecrets.org/pfds/overview.php?type=W&year=2014&filter=A&sort=A

There are plenty of Dems who are not millionaires. The real problem is that very few CONgress critters ARE NOT millionaires after being in DC for 6 years. IOW, many start reasonable net worth, BUT with less than 6 years of a supposed modest salary, they are rich.
And that is Both GOP and Dems.