THOSE WITH a yen for political caucuses and a taste for sunshine will be pleased to hear that another contest comes between last weekend's Michigan Republican convention in Grand Rapids and the caucuses in icy Iowa Feb. 8: Hawaii Republicans are going to hold a straw poll tomorrow. Enrolled party members -- any Hawaii voter who signed a card pledging to support the party -- will assemble from the state's 240 precincts and elect state convention delegates, who will then caucus and cast votes for presidential candidates. The result isn't binding on the state convention that will actually choose national convention delegates some time in April or May or June. But it is one of the nation's first Republican contests and is now the subject of some controversy.

The controversy arises because the poll was originally scheduled for Jan. 27, then postponed by the party's executive committee, and now has been rescheduled. The early line had Bob Dole as the favorite: he addressed last February's Lincoln Day dinner there; his moderate politics seems attractive; his name is on the pineapple cans. But in the first three weeks of 1988, the number of Republican Party members zoomed up from 11,500 to 17,500, and old-timers feared they were about to be outnumbered by supporters of Pat Robertson. So pro-Dole party leaders postponed the straw vote. At this the Robertson campaign understandably yelled foul.

In fact, the Republicans were asking for trouble with this device. Straw polls are one of the sillier techniques of presidential politics, and the Democrats have mostly suppressed them: one candidate's ability to pack the meeting hall in a contest that's not for keeps is not a reliable measure of his own appeal and not a fair measure at all of his opponents' drawing power in contests that really count. In any case, the Hawaiian straw poll will be held eight days later than originally scheduled -- time enough for the Robertson campaign to demonstrate its organizing ability once more before Iowa.

The Robertson campaign's attacks on party rules recall Jesse Jackson's denunciations of the Democrats' rules four years ago. In both cases the candidates have identified some small but real abuses, but have not persuasively claimed that the system was illegitimate. Mr. Robertson has a legitimate complaint against the Hawaii Republicans who postponed their straw vote, but this is small stuff. His followers are not persuasive when they claim that the Bush and Kemp campaigns are cheating in Michigan because they insisted on following state court rulings. There is always a little scuffling about the rules, especially in caucus states where state laws and party rules are not artfully drafted and reasonable people can disagree about their meaning. But no serious injustices have been done Mr. Robertson, and he will have his chance in Michigan, Hawaii, Iowa and the primary states that come after to show how well he can do.