A campaign that started out with all the earmarks of a vendetta took a surprising turn toward amity in Kentucky last week as Harvey Sloane (D) appeared headed for an easy victory in Tuesday's Democratic Senate primary.

The potential for a bruising intra-party scrap emerged earlier this year when Sloane's onetime friend, Gov. Wallace Wilkinson (D), recruited John Brock into the race to punish Sloan for failing to support Wilkinson in his 1987 gubernatorital bid.

But Brock, the state superintendent of public instruction, has been underfunded from the start. Last week Wilkinson pulled out of a scheduled two-day statewide fly-around with him and then suggested Brock get out of the race in a show of party unity. Brock turned down the suggestion.

The Republican candidate will be Sen. Mitch McConnell, considered by Democratic strategists one of the Senate's most vulnerable incumbents. Sloane is expected to make an issue of McConnell's heavy receipt of honoraria -- one of the same issues McConnell used in 1984 to unseat Walter "Dee" Huddleston (D).

Meantime, in Kentucky's 3rd Congressional District, 10-term incumbent Rep. Romano L. Mazzoli (D) is facing a stiff primary challenge from Jeff Hutter, who is stressing his support of abortion rights and his opposition to last year's congressional pay raise. Mazzoli, who has refused to accept political action committee money, is being outspent in the three-way race -- a rarity for an incumbent.