Hoping to out-Iowa Iowa, Florida's Democratic and Republican parties have scheduled presidential preference state conventions for November. The parties hope to make Florida the first state in the nation to declare its choice, though neither party will take a binding vote.

The State Republican Executive Committee voted here today 47 to 36 to hold a mini-convention after leaving Ronald Reagan's state campaign chairman argue against it and a supporter of Rep. Philip Crane (R-III.) argue for it. Crane attended the executive committee meeting, the only candidate to do so.

The Republicans will hold a one-day session Nov. 17 in Orlando solely to take the straw vote to determine their first and second choices. The Democrats will meet Nov. 16-18 in St. Petersburh to discuss their platform.

"But we need a reason for 2,000 people to pack up their luggage and drive of fly to St. Petersburg and spend money for hotel rooms," sais Greg Farmer, executive director of the State Democratic Executive Committee.

"Being able to be the first organized body in the nation to express a preference in the presidential election is the kind of incentive that is going to get people there."

The Democrats' vote is also scheduled for Nov. 17, despite Farmer saying he thought the Democrats and the Republicans had worked out a plan to meet on different weekends.

Crane's most prominent Florida supporter, former under secretary of the treasury Jerry Thomas, said he didn't like the idea of sharing the day with the other party either.

"If it's just Republicans, the head lines will read 'Regan and Crane,'" he said. "If it's the same day as the Democrats, the headlines will say 'Reagan and Carter.'"

Thomas' worry about headlines illustrates the importance of being the first state to give a candidate an endorsement. When a barely known Jimmy Carter led all other candidates in the Iowa Democratic caucus Jan. 19, 1976, he was propelled from "Jimmy Who" to "Jimmt Contender."

Because the Iwoa caucus was the first test of the candidates' strength in the election year, it offered reporters and other politcal observers the first chance to identify the real leaders in a crowded pack. Iowa drew important attention to the obscure former governor of Georgia, particularly after he also won the New Hampshire primary.

The Republican pack for 1980 already promises to be crowded. Winning early enough to establish the momentum and glamor of a frontrunner is important to every Republican candidate and reporters will look for the strengths or weaknesses of President Carter in Democratic votes.

As the Florida party leaders well understand, each reporter will want to be the first to spot a trend. That guarantees many reporters on hand, lots of publicity for the candidates and a sense of importance for the delegates who decide the outcome.

In 1976 Florida enjoyed prestige with the nation's third presidential primary, and the second really important one after New Hampshire. Now Texas is threatening to crowd Florida by holding a primary the same day.

Crane, who estimated he has already made "16 or 17" trips to Florida since he declared his candidacy in August, was delighted by today's vote. He said he will be in this state every month from now on.

"You don't expend this kind of time and energy to come in second," he added.

Reagan's state chairman was more subdued. Said Tommy Thomas," Now we gotta get to work." CAPTION: Picture, REP. PHILIP CRANE . . . plans lots of Florida trips