How many times congressman can be elected?

Answer 1

In the United States, there is no federal law that limits the number of times a congressman can be elected.

In fact, in U.S. Term Limits, Inc. vs Thornton (1995), the Supreme Court ruled that the states are forbidden from enacting limits on their congressmembers, as the matter is one of Federal law, and actually, of Constitutional law. That is, the qualifications for congress are set in the Constitution, and may not be changed without amending it.