Mitt Romney is a nice man. He might be the nicest man ever to run for president. He has been married to the same wife for 42 years, has five kids who are as nice as he, has given millions in charity, had a sterling business career and gave of himself in public service. He shut down his business to save a teenage runaway’s life. He rescued a family and their dog from drowning. He folded laundry and brought Thanksgiving dinner for his neighbors. He doesn’t like to brag. He doesn’t spend on himself excessively. He is nice, nice, nice. Now he’s got to forget nice. Seriously, it’s killing him.

More to the point, he has got to stop giving President Obama every benefit of the doubt even when the facts don’t warrant it. The campaign says that the administration sent “mixed messages” and Obama was “confused” and “slow” to react to the attacks on our diplomatic missions. Wrong. Even the New York Times has figured out that the administration knew it was a terrorist act and yet kept telling Americans it was a spontaneous reaction to a movie. He certainly can say what Sen. John McCain (R-Ariz.) did on CNN on Sunday:

If Romney can’t bring himself to call the president a “liar” on Libya, then say, “He didn’t level with you” or “It doesn’t pass the smell test” or “He told you things that weren’t true” or “He wasn’t candid with you.” After Sept. 11, 2001, he can remind voters, President George W. Bush kept us safe; Obama has not, and we have four dead Americans at the hands of jihadists.

When criticizing the president, Romney often takes the edge off. He says, “The economy is worse after four years.” No. The truth is: “President Obama’s policies made us worse off than we were when he took office.”

Others can postulate why Romney lacks the instinct for the jugular. Maybe “nice” is part of his self-image that he just can’t drop. Maybe he thinks his parents wouldn’t have approved. I don’t know, but he’s got to stop pulling punches and take the fight to the president.

This doesn’t mean he has to be insulting or rude. He doesn’t have to engage in Al Gore-like sighs in the debates. He doesn’t have to interrupt. But he does have to lay it on the line. He can smile when he says, “This president won’t admit we face an ongoing jihadist attack, so he didn’t keep our diplomats safe and he won’t keep us safe in the future.” He doesn’t need to yell when he turns to the president and says, “You know, you say this is the best anyone could have done.But this is the worst year in our economic history that wasn’t a recession. You really think the worst ever is the best we can do?”

Romney not only needs to excite his base (which some straight talk will certainly do) but also to project strength and certainty. (If you reelect him, we’re not going to get better. If you elect me, things will.) Independent voters don’t like name calling, but they do have to understand why voting for Obama would be a disaster.

Either Romney or his advisers (or both) are confused about “nice.” They think Ronald Reagan won because he was “nice.” He was nice, but he won in 1980 because he communicated a compelling message in a way that ordinary voters could understand. (Go back and check. Reagan wasted no time saying that Jimmy Carter was a good father or really had tried his best. Who cared?)

The opposite of “nice” is not Sen. Bob Dole (R-Kan.) growling that his opponent should “stop lying about my record.” Romney can smile and show good humor. He can be self-deprecating. But he can’t trim his sails or give Obama an out.

Just as he wasn’t very “nice” when he tore Newt Gingrich apart before the Florida Republican primary or dismantled Rick Santorum in the last GOP primary debate in Arizona, he needs to leave “nice” in the locker room for the rest of the campaign.