Chicago — With the polls showing strong public support for the Reagan administration's rescue operation in Grenada and a continued drop in inflation and unemployment, it's not a bad moment to be a Republican.
At least that's the way the nation's 16 Republican governors are talking these days at the annual meeting of the Republican Governors Association (RGA) here.
''Reaganomics a year ago was used as a negative term,'' observes RGA chairman Robert D. Orr, governor of Indiana. ''Today it isn't used at all because the meaning (doesn't apply).''
''My belief as of this moment is that the President will win and that he would carry Illinois,'' says Illinois Gov. James R. Thompson, who has just been named chairman of President Reagan's Illinois reelection campaign.
Governor Thompson's confidence stands in marked contrast to a recent poll by the Chicago Sun-Times and the local NBC affiliate which found that the majority of voters in seven of the 10 most populous states, including Illinois, do not want to see Mr. Reagan reelected. Those majorities would prefer either John Glenn or Walter F. Mondale, the leading Democratic contenders.
Yet most of these Republican governors readily concede that some of their GOP colleagues were defeated a year ago at the polls in part because of the unpopularity then of Reagan's economic policies. The GOP took a net loss of seven governorships.
''It was an extremely difficult election,'' says Governor Orr. ''Many of the things put into effect by Reagan were tough measures that were difficult for people to accept.''
This fall another incumbent Republican governor - David C. Treen of Louisiana - lost his bid for reelection, so in January the GOP total falls to 15. Governor Orr notes that GOP gubernatorial ranks fell to 12 in 1976 before President Reagan's 1980 victory helped to swell the ranks. He says the number is moving back to ''relative equality'' but that there are too few contests in 1984 to make it by then.
Yet most governors here, like their Democratic colleagues, have had to make deep cuts in spending and substantially raise taxes during the last year. These moves were needed to make up for cuts at the federal level and lost taxpayer revenues during the recession. And some here are sharply critical - though careful not to lay the brunt of the blame on President Reagan - of Washington's failure so far to raise taxes and get a firm handle on the growing federal deficit.