It's late in a long day of campaigning, but Sen. Bob Dole (R-Kan.) is always up for a little political gossip. Now he's listening avidly to the story of how Strom Thurmond, his 76-year-old Republican colleague who is running of reelection to the Senate, recently slide down the shiny pole of a South Carolina fire station three times to show photographers how youthful and vigorous he is.

"That's bad," Dole says with a grin. "He may be giving Reagan ideas." Ronald Reagan, 67, is the man Dole considers his leading opponent for the 1980 Republican presidential nomination. "If Reagan does it, we'll grease the pole."

Dole laughes. The others in his car laugh. Laughter is the protein of the Dole-for-president campaign, a tiny but boundlessly energetic road show that is playing so many burgs and boroughs these days that an outsider can't keep track them.

Bob Dole is hooked on policits, and there is no methadone-like substance that he can substitute for the straight stuff he craves regularly.

He came to a Republican dinner in the new, federally financed fire house here in Milford the other night, and the local bigwigs ushered him to a place at the head table. He sat down - for a moment. Then he popped up, walked to the crowd, and began shaking hands with each of the 400 souls present.

Where does he get the energy for displays like that, Dole was asked later. "Oh, I do it every time," he replied. "Usually I try to get into the kitchen, too."

In Delaware, Dole was campaigning for Jim Baxter, the laconic Republican candidate for Democrat Joseph Biden's Senate seat. Biden is ahed of Baxter by a long distance, according to both polls and the judgments of local politicians, but that mattered little to Dole.

"I guess Biden isn't having any trouble sleeping at night," Dole quipped as he finally ended his work here, climbing into a two-engine plane at 9 p.m. to return to Washington.

No matter. Dole valiantly told every audience he'd seen in Delaware that in his last Senate campaign he'd been far behind in the polls as well, but that hard work in the final days had put him over the top on election day. He smiled every time Baxter introduced him as his "personal friend," and he urged everyone in sight to contribute to the Baxter campaign, which is running on something Baxter uses in his normal line of work - chicken feed. (Baxter raises broilers.)

In the process Dole reminded a lot of Republicans that he was available to run for president, and he met some people who could help him in that. Specifically, he met a roomfull of wealthy Republicans at the Wilmington Club who - as Dole himself put it later - "could probably finance a pretty good campaign all by themselves."

They were the elders of the Delaware establishment. Republicans who has donated at least $500 each to Baxter's campaign.

With generously poured cocktails in hand, they stood around a room in the downtown club to meet Dole. "I met five people named du Pont," Dole said later of his experience in that room. One of them was the governor, Pierre S. (Pete) du Pont, a popular Republican.

Later, Paul Russo, Dole's traveling companion and aide for all occasions, made a note to get a list of those who attended the reception at the Wilmington Club. That is the sort of list any budding Republican presidential candidate would love to have.

Dole has been running round the country all year on these politica forays, but that's nothing new. He's been doing it for years, since before he was Republican national chairman in 1970-73. Gerald R. Ford made Dole a national figure by choosing him as his running mate in 1976, but the Kansas senator acknowledges that he was toying with national ambitions for some time before that.

In fact, Dole seems to be one of the those politicians for whom presidential ambitions come naturally, almost spontaneously. He loves the game he is playing, and it obviously strikes him as perfectly normal to want to be the best player in the game.

This year he believes he has a real shot at the big brass ring in 1980. His reasoning goes something like this: He has made a lot of friends in the GOP, and with trips like this one to Delaware he continually adds more. He has support in all wings of the party, from Ford's to Reagan's, plus a national reputation and an effective campaign style. Now he has found a new position - a kind of affirmative conservatism, in Dole's view - that can help him project an image as a positive Republican candidate who can make proposals instead of simply opposing Democrats' ideas.

Dole realizes he is a longshot. He notes in speeches that the polls show Republicans divided in their presidential preferences. 40 percent for Reagan, 40 for Ford, 10 for "others" and 10 undecided. "We're in there with the others,'" Dole says.

But he's hopeful that Reagan will stumble, or that anti-Reagan elements will eventualy pick Dole as their gladiator, or simply that lightning will strike sometime between now and the Republican National Convention in the summer of 1980.

Dole's new position is to court groups traditionally ignored or written off by many Republicans - blacks and Jewish groups for example - and to offer "positive" new program ideas. Here he endorsed a constitutional amendment that would require a balanced federal budget, and a limited health insurance scheme to provide catastrophic illness coverage to all Americans through private insurers.

His new, positive program seems no more adventurous than that, and he appears to admit in his public statements that the problem he sees is one of image. "There is a perception out there in the country," he says repeatedly, "that somehow the Republican Party is a negative force in politics." That must chang, he adds, if the GOP is to win any elections. "We don't need any more moral victories," he usually adds. "They don't vote in Congress!

As for his own image, Dole professes confidence that it's fine. He vigorously denies that the 1976 campagin tainted him as some type of crude hatchetman, though he acknowledges that he and some associates went back and watched tapes of all his public performances in 1976 to see what all the fuss was about. They found nothing to justify any fear for the future, Dole insists.

Dole thinks the political press based in Washington and New York invented this notion, and he says heatedly that people "out in the country" don't know anything about it.