Rep. Howard Nielson, R-Utah, has a commanding 3-1 lead over both Democrats seeking to replace him, according to a new Deseret News/-KSL poll.

Even more embarrassing for those Democrats - former U.S. Senate candidate Craig Oliver and Utah County Democratic Chairman Robert W. Stringham - is that 70 percent of residents don't yet know which of them they support for the Democratic nomination, even though the state convention is next month.For example, when residents were asked whether they would vote for Oliver or Stringham in a primary election, 70 percent were undecided, 16 percent said Stringham and 13 percent said Oliver.

The poll, conducted April 19 to 21, has a 7 percent margin of error - so that primary race is considered a dead heat.

But whoever becomes the nominee has his work cut out for him, considering the overwhelming lead that Nielson holds over both Democrats.

When residents were asked for whom they would vote if Nielson ran against Stringham, 51 percent said Nielson, 16 percent said Stringham, 6 percent said American Party candidate E. Dean Christensen and 27 percent did not know.

Almost the same results came when Nielson was paired against Oliver. In that case, 53 percent favored Nielson, 15 percent favored Oliver, 6 percent opted for Christensen and 26 percent said they didn't know.

Somewhat surprisingly, neither Democrat says he is worried about the poll. Both say they are doing as well as they thought they would.

"It's still far too early in the campaign to take any significant reading in this race," Oliver said.

When asked if he could beat Nielson, Oliver said, "Yes, no question about it. This is one of the most economically depressed areas around . . . and Nielson has done nothing to solve it. He already said he would not run again in 1990, so he just wants two more years to pad an already bloated pension."

Even though the poll shows him even with Stringham, Oliver predicts that name recognition achieved in 1986 when he ran against Sen. Jake Garn will help gain the Democratic nomination by either getting 70 percent of delegate votes at the state convention next month or by winning a primary.

Stringham disagrees strongly, saying he fully expects to be the nominee and the man who will eventually beat Nielson. "Right now, the poll shows we are right where we thought we would be, and in fact are a little better." He said his numbers should improve once he begins his advertising campaign.

Nielson said he is happy he already is favored by more than 50 percent of those polled. He said once that more attention is given to the campaign and issues become more apparent, he feels he will pick up his share of the undecided vote and wind up with more than 60 percent of the final vote.