Rep. Mike Lawler, a New York Republican, said the Wisconsin senator should "stop peddling conspiracy theories about the worst terrorist attack in our nation’s history."

Venturing into long-debunked conspiracy theories, Johnson said World Trade Center Building 7 could not have come down “in any other way than a controlled demolition."

It’s been two decades since 9/11, but a Republican lawmaker still has questions about what happened that day. Wisconsin Sen. Ron Johnson, chairman of the Senate Permanent Subcommittee on Investigations,