Wandering among the delegates, politicians and media types who populated the Democratic and Republican national conventions this year were two men with little interest in the candidates but plenty of interest in their more creative supporters.

Together, Larry Bird (curator for the Smithsonian, not the star basketball player) and Harry Rubenstein of the National Museum of American History scoured the crowds in search of tchotchkes that could be added to the Smithsonian’s collection of political memorabilia. It was far from their trial run: Every election season, the two pack their bags and travel to the New Hampshire primaries and the national conventions in search of the most creative signs, hats and other political paraphernalia.

“Our general mandate is to try to collect material of national significance,” said Rubenstein, chair of the Division of Politics and Reform at the museum. “We tend to be very interested in things that are personally made or very expressive or have a unique quality to it.”

The two have been traveling to the conventions since the 1980s, adding to the expansive collection that contains some 100,000 objects dating back to the early days of the republic. It features such kooky knick-knacks as “Johnson Juice,” small soda cans used to promote Lyndon B. Johnson back in the 1960s; John F. Kennedy hats, the famed straw hats that are so often associated with campaigns; and Goldwater glasses, plastic black glasses like those worn by Barry Goldwater.

After trips to Denver and St. Paul, Minn., the history buffs say there was no shortage of memorabilia at this year’s conventions. Rubenstein said the number of campaign tchotchkes dropped off in the 1980s, but that the advent of the Internet saw a rebirth in the industry. Now many Web sites sell shirts, pins and signs bearing the faces of nominees Sens. Barack Obama (D-Ill.) and John McCain (R-Ariz.).

In August, Bird and Rubenstein collected everything from a button featuring Obama and Hannah Montana — an attempt to woo the youth vote — to a homemade red- sequined hat adorned with donkeys and the word “unity.” While they do collect official and professionally made campaign gear, it’s the homemade items that really get Bird and Rubenstein excited.

Rubenstein said that many delegates will make a hat ahead of time or grab a free hat used as a promotional tool by a media outlet and use it to create their own pieces of campaign art. The creativity of delegates often expresses itself in hats, since delegates are not allowed to bring any handmade signs onto the convention floor, Bird said.

“They do not police hats at all, so you can wear the most offensive statement on a hat and it isn’t policed in the way that putting that statement on a piece of card stock is,” he said.

Some delegates take that license to a new level. For instance, at the 2004 convention, Bird and Rubenstein collected one made out of an old shopping bag. Because the person, a supporter of Rep. Dennis Kucinich (D-Ohio), couldn’t bring in a sign, she scribbled her views on the side of the bag and wore it atop her head.

“Can you image somebody wearing [that] during the convention as a way of making their own kind of statement?” Rubenstein said with a chuckle. “These are the kinds of things we look for — there’s a real sort of personal expression.”

Because the hats are often important to the delegate, Bird and Rubenstein will give the person a business card and ask that the hat be sent once the convention has concluded. The red-sequined hat, spotted on the floor of the Democratic National Convention, is the first to come in from this year’s expedition. A woman named Ruth Rudy shipped it from upstate New York.

“I think the unity theme really struck me,” Bird said.

Rubenstein added that he and Bird are looking not only for creative creations, but also for items that epitomize the moment, as the unity hat did. Bird said that when he asked Rudy to send the hat, she recognized him from the ’92 convention, at which he had collected from her.

Another hat from this year’s Democratic convention stands out in Bird’s mind, though the owner has not sent it to the museum.

“The one that I liked was from a woman from Georgia, and she had a hat that had little doll furniture like it was a bathroom on top of her hat with money being flushed down the toilet,” he said. “It said, ‘Keep America’s economy from being flushed down the drain.’”

Bird and Rubenstein are hoping that more hats will trickle in as the weeks pass, though typically only 25 percent to 30 percent of the people they talk to will actually mail their memorabilia to the museum.