Sen. Jim DeMint (R-S.C.), who has bucked the establishment to support tea party candidates, said Sunday that his party is “dead” if it wins a majority this fall and doesn’t stick to conservative principles. Republicans held majorities in both chambers, and George W. Bush was in the White House when DeMint moved from the House to the Senate in 2005. But he said the party didn’t live up to its promises. “Republicans didn’t do what we said we were going to do,” he said Sunday on CNN’s “State of the Union.” “We spent too much, we borrowed too much. And...