AS VOTE NEARS, POLITICIANS STRIVE NOT TO OPEN MOUTH, INSERT FOOT

As the 1994 election heads to a close, candidates are finding they have to be extra careful of what they say. A last-minute gaffe can inflict serious political injury.

Vice President Al Gore, about as cautious and unflashy as campaigners get, stumbled twice in the past few days with utterances that blew up in his face.One was an attack on Republican Virginia Senate candidate Oliver North. Gore said North "is banking on the fact that he can raise enough money from the extreme right wing, the extra-chromosome right wing."

Well, Gore later said it was an offhand comment to disparage the right wing. But mental-health advocates took strong exception, noting the link between "extra chromosome" and Down syndrome, a genetic defect that can lead to retardation. People with Down syndrome have 47 chromosomes instead of the normal 46.

To make matters worse, Gore's remarks came during Down Syndrome Awareness Month.

Gore also got scorched when he attacked the immigration policies of California Republican Gov. Pete Wilson. Wilson noted quickly and gleefully that Gore himself had voted for similar policies when they both were in the Senate.

In another California race, Republican Senate candidate Michael Huffington also found himself tangled in his own words on immigration.

He admitted his family employed an illegal immigrant as a nanny from 1989 to 1993 - bringing charges of hypocrisy from his rival, Democratic Sen. Dianne Feinstein. Huffington squirmed, then blamed his wife.

In the hot Virginia Senate race between North and Democratic Sen. Chuck Robb, North found himself having to backtrack after telling schoolchildren that he'd never lied to Congress on the Iran-Contra affair. In fact he has admitted doing so in the past.

"It's very important not to commit a gaffe in the final stretch if the race is close," said James Thurber, a political scientist at American University. "If you're way ahead, it probably doesn't make any difference."

That caution applies equally to President Clinton as he stumps hard for Democratic candidates across the nation.

"Given the fragility of Clinton's approval ratings, little things can make a difference," said Thomas E. Cronin, president of Whitman College in Walla Walla, Wash., and the author of several books on American politics and the presidency.