Arkansas' angry and unpredictable campaign for the Senate seat long held by the late John L. McClellan will be effectively settled today in a runoff Democratic primary election between Gov. David Pryor and Rep. Jim Guy Tucker.

The easy-going Pryor, 43, and the intense, hard-charging Tucker, 34, have been sniping at each other daily since they ran first and second, respectively, in the initial Democratic primary May 30.

The key issue in the last week has been the revelation that Pryor's campaign manager privately approach a state official about a pending utility rate case involving firms owned by a Democratic Party kingmaker.

The winner of the Democratic run-off is expected to win the Senate seat in November.

Primary voters in Maine will choose candidates to compete for the governor's chair being vacated by Independent James Longley, who is retiring even though he would have been favored to win a second term.

There are three-way races in both parties for the nomination to succeed Longley. Dealing with Indian land claims has been a central issue in the gubernatorial campaigns.

Incumbent Democratic Sen. William Hathaway and Republican Rep. William Cohen were unopposed in primary campaigns Maine's Senate nominations.