ROBB'S MODERATE IMAGE WINS OUT

In Virginia's mud-slinging battle of the ex-Marines, incumbent Sen. Charles Robb triumphed by convincing many moderate voters that his own ethical problems were less serious than those of GOP challenger Oliver North.

In exit polls, 60 percent of voters cited North's involvement with the Iran-Contra affair as a factor affecting their choice. In contrast, 40 percent said Mr. Robb's dalliance with a beauty queen and presence at parties where drugs were used swung their ballot the other way.

Robb won Virginia moderates 2 to 1 and took over 90 percent of the black vote. North was hurt by active opposition from Virginia's GOP Sen. John Warner and criticism from Nancy Reagan.

Good weather all across the state also fostered the big turnout Democrats had hoped for. ``I saw the weather report four days out, and I said `bingo','' a relieved Robb said after his victory speech. In his concession North sparked speculation that he would try for office again.