Members of Congress could be excused if they are puzzled by the recent run of stories about President Obama's commanding lead over Mitt Romney on the question of who is the more likable candidate. Those who served with Obama in the Senate remember a cool, often aloof, colleague who forged few lasting friendships in his brief tenure. And those who deal with him now see a chief executive who rarely reaches out to them in a personal way and seems to abhor the schmoozing practiced by so many of his predecessors. When asked by Rolling Stone recently about his relationship with Republicans in Congress, the president replied, "It's not frosty. This isn't personal."

That's the Barack Obama that Congress knows: all business, as befitting a man who came to the White House from Congress, where likability is not a big factor in campaigns.

There is a reason that Obama is only the third sitting senator ever to be elected president, after Warren G. Harding and John F. Kennedy. Lawmakers can be very big in their districts or very powerful in their states. But the ways of Capitol Hill — the odd phrases such as calling a female lawmaker "the gentle lady," the weird mental contortions, like "I actually did vote for the $87 billion before I voted against it" — don't easily translate to a national audience. Rick Santorum is only the latest to discover this. Romney mocked him in the final GOP debate in Mesa, Ariz., for taking "a very tortuous route" to explain his actions when he was in the Senate. Santorum stumbled badly in trying to explain why he voted for No Child Left Behind but now opposes it. "I have to admit I voted for that," he said. "It was against the principles I believed in. But you know, when you're part of the team, sometimes you take one for the team, for the leader."

Likability is not something many lawmakers worry about. Ohio Democrat Howard Metzenbaum was as abrasive as they come. But he served almost 20 years in the Senate, gaining a reputation as a man who didn't care what anybody thought about him as he battled corporate power. Ohioans knew he was an SOB. But he was their SOB. That works in Congress but would have doomed Metzenbaum had he tried to go national. The difference is that Americans invite the president into their living rooms and kitchens and bedrooms through television.  It becomes personal.

For Obama, this hit home early in his 2008 campaign and may have cost him the New Hampshire primary. At a key debate on Jan. 5, rival Hillary Rodham Clinton was asked why the state's voters "seem to like Barack Obama more." Well, she responded, "that hurts my feelings." Calling Obama "very likable," she added, somewhat plaintively, "I don't think I'm that bad." At that point, Obama had his most unlikable moment of the campaign, stating rather dismissively, "You're likable enough, Hillary." For many women, it was a reminder of every put-down they had ever endured from a man. Clinton pulled out the upset win in New Hampshire days later.

But the numbers didn't lie. Voters did like Obama lots more than Clinton. Heading into that debate, Obama's favorables as measured by Gallup were 59 percent to 32 percent, while Clinton's were tied at 48 percent. Obama built on that advantage in the fall campaign. At the time of the election, his favorables were 62 percent to 34 percent; Republican John McCain's were 50 percent to 44 percent.

It was just the latest manifestation of what the polls have told us since 1984: Ronald Reagan over Walter Mondale; George H.W. Bush over Michael Dukakis; Bill Clinton over Bush; Clinton over Bob Dole; George W. Bush over Al Gore; Bush over John Kerry; and Obama over McCain. In every instance, the candidate seen as more likable won the election. In some of those races, the gap was so glaring that the less likable candidate struggled to change the numbers. In 2000, strategists for Gore finally gave up and made gag buttons, which Gore sometimes wore under his lapel, saying "I'm Al Gore and I don't like you either."

Today, though, Romney's backers are not ready to surrender even though the most recent NBC News/Wall Street Journal survey shows the widest-ever gap, with respondents liking Obama 15 points more than Romney. Republican pollster Whit Ayres recently interviewed four groups of independent voters who voted for Obama in 2008. They "still like the president," he found. But, he added, that "does not prevent many of these independents from concluding that Obama has not delivered according to their expectations."

Ayres told National Journal Daily, "We want to like the people who lead us. But liking them is not as important as respecting them for their leadership abilities.... You are who you are. [Romney] will never be a hail-fellow-well-met. He will never come across as a great guy to go have a beer with.... But he can be a very well respected chief executive who knows how to get the economy going."

Of course, that would be an easier sell if Romney could get more voters to like him. Because, unlike what Obama said about Congress, when a presidential candidate appeals for votes, it's personal.