It’s hard to find the funny in this year’s presidential race, but Mo Rocca, formerly a correspondent for Comedy Central’s “The Daily Show,” is doing his best. The results can be seen in “How They Won: 7 Secrets to Winning the Presidency,” premiering Tuesday at 8 p.m. on The History Channel, Sunflower Broadband Channel 61.

But first, Rocca weighs in on the controversial appearance of “Daily Show” host Jon Stewart on CNN’s political-debate show “Crossfire” last week.

Supposedly on to promote the book he co-authored with his show’s writers — which bears the weighty title of “The Daily Show with Jon Stewart Presents America (The Book): A Citizen’s Guide to Democracy Inaction” — Stewart instead lashed out at “Crossfire” hosts Paul Begala and Tucker Carlson over what he perceives as weaknesses in their show. In particular, Stewart seemed peeved that the 35-year-old Carlson still wears a bowtie.

Rocca, who considers Stewart a “mentor,” has given some thought to this, especially since he’s been known to don a bowtie in the past.

“Remember,” Rocca says, “Jon wasn’t excoriating fake journalists who wear bowties. So on that count, I’m safe. He said, ‘You’re 35 years old and wearing a bowtie.’ I have not worn a bowtie for a year and a half. I’m 35 also. So the last time I wore a bowtie is when I was 34.

“Thirty-five is an important line of demarcation, because at 35, you can run for president. Before that, you cannot. I don’t think we should have a candidate for president with a bowtie, and I think that’s what Jon was trying to say, simply that 35 is an important watershed for a man, and the bowtie is no longer acceptable at that point.”

As important as the whole bowtie theory seems to be, it is not one of the topics covered in Rocca’s History Channel special, in which the amateur presidential historian (he’s visited a lot of presidential graves) reviews a couple centuries or so of American elections in search of common threads for success.

The results are: “Be the Common Man”; “Have a Ne’er-Do-Well Brother”; “Pick a Presidential Pooch”; “Better Hair Matters”; “Mudslinging 101” (yes, name-calling is an American tradition dating back to the Founding Fathers); “Have a Great Theme Song”; and “Have a Lot of Money.”

“There’s a question that comes up a lot,” Rocca says, “whether it’s at book signings or college campuses, people saying, ‘This is such an ugly campaign, is it hard to find anything to laugh at?’ I’m proud to be a fun-dit, to put the fun in punditry.

“My hope is, in a strange way, that looking at the importance of things like hair, pets, siblings — hopefully that will be sobering to people. It may wind up enraging people even more.

“But a lot of the categories we came up with are almost euphemisms for a test of manliness.”

Of all the subjects covered in the special, Rocca claims expertise in only one area, that of White House critters. He’s currently on the road promoting his new book, “All the Presidents’ Pets: The Story of One Reporter Who Refused to Roll Over,” published Sept. 28 by Crown.

“The whole wall of secrecy around the president,” he says, “it begs the question, what are chief executives hiding? The obvious answer is, anything that would diminish the image of the super-heroic, omniscient god, basically.

“I just happened to know everything about all the animals that have lived in the White House. I’m willing to say that, on this topic, I am an expert.”