By finishing third in last night’s Iowa caucuses, Marco Rubio joined Donald Trump and Ted Cruz as a candidate with a realistic chance of winning the Republican presidential nomination. Rubio pulled himself out of the pack of long-shot candidates and sure losers in the large GOP field – by itself, an important achievement.

What made Rubio’s showing especially impressive was how close he was behind Trump, who had led in pre-caucus polls. That wasn’t all. Rubio not only survived a wave of nasty negative ads by Jeb Bush, his one-time political ally in Florida. He also overcame complaints by Iowa Republicans that he had taken the state’s role as the first contest in the nomination battle too lightly and not campaigned there enough.