Arizona Sen. John McCain threw his support behind Wyoming Sen. Mike Enzi in his primary race against fellow Republican Liz Cheney.
The Arizona Republican told Candy Crowley on CNN's "State of the Union" that most who have served with Enzi are supporting him over the eldest daughter of former Vice President Dick Cheney.
"Mike Enzi is the epitome of a workhorse in the Senate," McCain said.
Liz Cheney launched her campaign Tuesday to unseat the three-term incumbent.
Cheney has struck a no-compromises tone and said it's time for Republicans in Congress to stop "cutting deals" with Democrats.
Still, she has declined to say whether she was referring to Enzi, who has expressed pride in being able to work with Democrats on some issues.
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