Sen. Dan Quayle is warning Republicans against overconfidence in the waning days of the presidential campaign, saying the GOP could end up like Thomas Dewey in 1948. Arriving here Tuesday night at the end of a long campaign day in Ohio, Kentucky and Indiana, Quayle said ``the polls have been all over the lot.'' ``We believe, in fact, we have a small but marginally insignificant lead,'' he told reporters. Two nationwide surveys released Tuesday night show the Republican ticket of George Bush and Quayle holding double-digit leads of 12 and 13 points in the final week before the election. Earlier, while campaigning for Indiana Lt. Gov. John Mutz, who is trying to succeed Robert Orr in Quayle's homestate of Indiana, the senator sought to deflect burgeoning speculation about whether his wife, Marilyn, might be appointed to fill his vacant Senate seat in the event of a Bush-Quayle victory next Tuesday. ``It's going to be Bob Orr's decision,'' Quayle said of talk within Republican Party circles in the state that Mrs. Quayle might be offered the vacant seat. During an interview last weekend on the syndicated program ``McLaughlin: One on One,'' Quayle's wife refused to flatly rule out such a possibility. ``I think it's a real honor for her to be considered,'' Quayle told reporters in Evansville. ``I'm not going to do anything to disrupt the discussion. ... Of course, we've got a family, and life is going to change a lot'' if the Bush-Quayle ticket is elected, he said. Quayle was appearing at a campaign rally today in this ``City on the Bluffs'' before traveling to Owensboro, Ky. He has appearances scheduled later in the week in Greenville and Spartanburg, S.C., and in Oklahoma and Alabama. The senator, who complained about last-minute scheduling changes dictated by the Bush campaign headquarters in Washington, seemed buoyed by two appearances in his homestate, one in Jeffersonville and the second in Evansville. Red, white and blue balloons sailed in front of a flag-waving, cheering crowd as the band struck up ``Back Home in Indiana.'' But when he arrived in Memphis in late evening, Quayle deflected questions which assumed a Republican Party victory at the polls. ``We believe this election could still go either way,'' he said. ``We're not taking anything for granted. That would be absolutely lethal.'' ``One way you can lose an election is to sit back, and relax, and we'll end up like Dewey did,'' Quayle said. He was referring to Thomas Dewey's upset loss to Democrat Harry Truman 40 years ago in an election that virtually all the experts had given to Dewey.