But the GOP had to spend over $1.2 million to keep control of the once-safe seat.
In a special election, Democrats see a shot at long-term gains in the red state.
He had said earlier that he would resign next year.
The Arizona Republican says the House ethics panel is looking at his "discussion of surrogacy" with female staffers.
What some might call cyberwarfare others apparently consider journalistic best practices.
Congress is currently considering expanding the U.S. national missile defense system, despite the fact that -- nearly 15 years after the Bush administration began deploying it -- it has not been demonstrated to work under real-world conditions and is not on a path to do so.