The most generous interpretation of Tuesday night’s results is that Mr. Romney’s campaign failed to make much of an effort in the contests. He did not make many personal appearances in the states, nor did he run a significant amount of advertising. And his campaign worked to diminish expectations in the day or two before the voting — a practice that can annoy voters who are undecided in the race if they feel like they are being told their vote doesn’t matter.

Why Mr. Romney’s campaign made these decisions is hard to say. One of the advantages of having a resource-rich campaign, as Mr. Romney does, is precisely that you are able to leave less to chance. Mr. Romney would have had the luxury of running commercials in Colorado or Minnesota, or of establishing a set of field offices in those states. Instead, his strategy was complacent. He gambled and paid the price, as Hillary Rodham Clinton did in the caucus states in 2008.

Fortunately for Mr. Romney, none of his rivals are in the same ballpark as Mrs. Clinton’s opponent, Barack Obama, as measured by metrics like fundraising, organizational strength, or oratorical skill. But Mr. Romney is not a strong enough candidate that he can afford more nights as bad as Tuesday.