WASHINGTON -- GOP Senate candidate Mike McFadden said Tuesday he favored a proposal introduced this week in the House that revokes passport and re-entry privileges for American citizens who fight overseas for Islamic militants.

The bill was introduced by Rep. Michele Bachmann Monday.

Bachmann's bill, dubbed the Terrorist Denaturalization and Passport Revocation Act, amends existing laws and rescinds re-entry privileges for people who join terrorist armies overseas. A companion measure was introduced by Texas Republican Sen. Cruz that goes a step further and allows the U.S. government to strip citizenship of any person joining military forces with countries at war with the United States.

McFadden's spokesman said he thinks Cruz's bill could be unconstitutional based on previous Supreme Court rulings on citizenship revocation.

Bachmann, who was on Fox News last night talking about her bill, endorsed McFadden at the May GOP convention in Rochester.

McFadden said in a statement Tuesday: "It is necessary that we have policies and procedures in place to prevent this from occurring and to ensure that trained terrorists do not come back to the United States with the ability to launch terror attacks here at home."

McFadden is hoping to unseat Democratic Sen. Al Franken in November. Expecting a Franken response to the legislation in the next couple hours.