Miller also issued a longer apology on Friday night for a tweet on his account that likened a potential Murkowski run as a Libertarian to prostitution.

"Throughout the campaign, I have had volunteers who assist in many areas, including assisting me in communicating through Twitter. This tweet was in poor judgment and the volunteer has been relieved of those duties," Miller said. "And while the comments have been misconstrued (they were directed at the Libertarian Party), I don't stand by those comments.

"The Libertarians are free to choose whomever they want to represent them. It's up to them to decide who best represents their values. I am a Republican Party U.S. Senate candidate, and look forward to representing that party's message of limited government and returning power to the states and the people who live in them. I certainly apologize to Senator Murkowski for any hurt feelings caused by this poorly conceived post."