Can a member of Congress be expelled?

No. Members of the Senate and House of Representatives are removed from office through a different process involving only the chamber of Congress in which they work. Under Article I, Section 5, clause 2, of the US Constitution, a Senator or Representative may be expelled if there is a formal vote on a resolution agreed to by two-thirds of the members of the Senate or House body who are present.

Article I, Section 5, Clause 2

"Each House may determine the rules of its proceedings, punish its members for disorderly behavior, and, with the concurrence of two thirds, expel a member."

**The above is true when the member has not committed a crime. Members of Congress at any level (state or federal) can not be impeached, but if removed from Congress can be indicted for crimes like any other citizen.