The big news in politics today is the announcement that Supreme Court Justice Sandra Day O’Connor plans to retire as soon as a replacement is confirmed.

The announcement is somewhat of a surprise, because it was expected that Chief Justice William H. Rehnquist, 80, would be the one to retire first. Democrats had been hoping to keep O’Connor on the bench because, while often siding with conservatives, she had long provided swing votes on liberal issues such as abortion.

The battle over the nominee to replace O’Connor now begins, with Colorado Circuit Court of Appeals Judge Michael W. McConnell a possible replacement. Expect some of Colorado’s highest profile elected officials to play a major role as the rhetoric heats up. Sen. Ken Salazar will likely be thrown back into the fray, as he was this spring when he played a vocal role in the fight over filibusters.