The see-saw presidential race between President Bush and Sen. John Kerry (D-Mass.) is a delight for political junkies. It’s also a delight for people who sell political memorabilia.

Vendors at both the Republican convention in New York and the Democratic convention in Boston say they’ve been ringing up stellar sales of buttons, jewelry and other politically themed trinkets.

“This has been the best election year since 1992,” said Mort Berkowitz, president of Bold Concepts Unlimited, a button and souvenir company based in New York’s Times Square.

Bill Clinton’s charisma — and his way of irritating detractors — made 1992 a banner year, Berkowitz said. In 1996, by contrast, Republican nominee Robert Dole deflated sales. In 2000, sales pegged to Democratic nominee Al Gore — even a button of his convention-podium kiss — sold surprisingly well.

This year, the closeness of the election and the fired-up bases of both parties have kept the cash register ringing.

“I think ideologues on both sides of the fence have taken seriously to this campaign, so button sales are way up,” said Berkowitz, who sometimes is known as the Button Baron of the Big Apple.

Stuart Fishman, who’s manning an official convention souvenir shop across from the Ed Sullivan Theater in Midtown, says his products have been selling briskly, despite the occasional Democratic customer who complains that they’d rather the storefront space still be home to a coffee house.

“For each delegate here, there are five people back home who they have to bring something back for,” he said.

While he and other vendors agree that simple designs, such as “W ‘04” with a stylized flag, are selling fastest, more outrageous items also are attracting attention. One popular one, labeled “Keep Bush on Top,” features an elephant mounting a donkey. (Though the button’s vulgarity seems ultra-modern, Berkowitz says that its “humping” iconography actually dates to the 1912 presidential bid of William Howard Taft.)

This year’s convention season has once again proved a truism in the souvenir business: The Republicans live up to their free-market principles in encouraging memorabilia sales. As in past conventions, the GOP offered a common exhibition space — a bustling ballroom at the New York Hilton — to souvenir vendors. There, exhibitors sold everything from presidential Christmas ornaments to cases of “W” ketchup — a Republican alternative to condiments made by ketchup giant Heinz, which is the source of the fortune inherited by Kerry’s wife, Teresa Heinz Kerry.

For the price of an exhibitor’s booth rental, entrepreneurs like John Murphy, who sells politically themed auction-style paddles for $5 each, or Bob and Emily Egan, who sell Bush family earrings for $3 a pair or two for $5, can lighten the wallets of GOP delegates.

The Democrats, by contrast, usually contract with a single vendor — Mark Weiner, who runs a company called Financial Innovations Inc. in Cranston, R.I. — who makes a modest selection of Democratic Party-approved items and then sells them at stalls in choice convention-city locations.

Independent sellers gripe about Weiner’s gig with the Democrats. Weiner is a big donor to Democratic candidates and organizations, giving almost $175,000 over the past three election cycles, according to data from the Center for Responsive Politics. Weiner did not return a phone call for this story.

Instead, vendors who want to sell at the Democratic convention have to carve out their own niches. Berkowitz made buttons for 24 state delegations in Boston and hustled from meeting to meeting.

Scott Stachel, a molecular biologist in Jackson, Wyo., joined up with a few friends to market a “Time Left” button that counts down the days, hours, minutes and seconds until (they hope) Bush loses on Election Day, then resets and starts counting down until Inauguration Day.

Thanks to word-of-mouth sales on the Web stemming from the button’s visibility at the Boston convention, the group has sold a few thousand copies at $9.95 a pop.

“Button Bob” Levine of suburban St. Louis, a Democrat who sells souvenirs at both party conventions, much prefers the Republican setup, despite his partisan leanings. This week, he said, he expects to rake in about three times what it cost him to make the buttons, excluding his exhibition-booth rent and other incidentals.

In a role-reversal this year, Democratic items seem to be unusually edgy, whereas Republican souvenirs — usually an outlandish bunch, with taste standards set by talk radio hosts — have been toned down a bit.

As expected, the exhibition floor includes variations on the notion that Kerry is a waffler or a flip-flopper, while one button says that the Massachusetts Senator “puts the rat in Democrat.”

But GOP officials required one vendor to remove from his shelves a button that read, “If They Take Our Guns, How Can We Shoot Liberals?” Maybe it has to do with the need to show a moderate GOP face, but the censored button’s sentiment hardly would have raised an eyebrow in the souvenir halls of San Diego in 1996 and Philadelphia in 2000.

By contrast, the riled-up grassroots base of the Democratic Party has produced a thriving market for anti-Bush material. While Republican items are still generally more outspoken than Democratic ones, some of the items on sale in major Boston venues were edgier than in the past.

Fishman, who set up shop in the lobby of Boston’s Marriott Copley Place, sold buttons that showed Vice President Cheney holding a dummy of President Bush on his knee. Another urged “Stop Cowboy Diplomacy.” Still angrier fare could easily be obtained from independent street vendors.

Proving that the destiny of all political slogans is to be recycled, one button spotted in New York City touted the “Pro-C.A.R.B. Diet — Cheney, Ashcroft, Rumsfeld, Bush.” An identical button was offered to Democratic conventioneers in Boston. That one, however, was dubbed the “No-C.A.R.B. diet.”