HELENA -- Both Republican U.S. Sen. Conrad Burns and Rep. Denny Rehberg lead trial matchups against potential Democratic opponents for the 2006 election and, as incumbents, are far better known among the voters, a new Lee Newspapers poll shows.

The telephone survey, taken May 23-25 of 625 likely Montana voters by Mason-Dixon Polling & Research Inc., has a margin of error of plus or minus 4 percentage points.

If the 2006 Senate election were held today, Burns would defeat state Auditor John Morrison, a Democrat, by a 49 to 34 percent margin, with 17 percent undecided. Burns leads among men by a 54 to 33 percent and among women by a 44 to 35 percent majority, with the rest undecided.

Burns, 70, is a former Yellowstone County commissioner and agricultural broadcaster who already has raised $2.2 million for the 2006 race. Morrison, 43, a Helena attorney, was elected to his second term as state auditor in November and announced his Senate candidacy in April.

"Burns is under 50 (percent) against Morrison, but at 49 (percent) I don't see him as vulnerable, but would keep an eye on him," said Mason-Dixon pollster Brad Coker. "If he were 44-45 (percent), I'd put it into the category of potential upsets. Right now, he could be doing a little better against Morrison, but he's not in the super danger zone."

In another test, Burns would defeat Montana Senate President Jon Tester, D-Big Sandy, by a 50 to 26 percent margin, with 24 percent undecided. Burns tops Tester among men, 56 to 25 percent, and among women, 44 to 27 percent, with the rest undecided.

Tester, 48, is an organic grain farmer who announced his candidacy last week by driving his tractor-trailer to major cities across the state.

A third trial matchup pitted Burns against former Missoula Mayor and ex-House Speaker Daniel Kemmis, with Burns leading 53 to 23 percent, with the rest undecided. Kemmis, who had been considering the race, announced Thursday he wouldn't run for the Senate after all.

The poll did not include two other potential Democratic challengers, Clint Wilkes, 55, a political newcomer from Bozeman who said he is running, and former Helena Rep. Paul Richards, 50, a freelance writer and editor in Boulder.

No Democrats have yet declared against Rehberg, a Billings rancher and developer seeking his fourth term in the House.

The poll did set up a trial matchup that showed Rehberg defeating state Rep. Monica Lindeen, D-Huntley, a potential challenger, by a 58 to 24 percent margin, with 18 percent undecided. Rehberg leads among men by a 60 to 23 percent margin and among women by a 56 to 25 percent margin, with the rest undecided.

Lindeen, 43, is a business entrepreneur who with family members started and later sold what became Montana's largest Internet service provider.

One other potential Democratic U.S. House candidate surfaced this week after the poll was launched and too late to be included. That was Rep. Larry Jent, D-Bozeman, an attorney who lost a bid for the Democratic nomination for Congress in 1996.

The poll also asked voters whether they recognized the names of these people and, if so, favorably or unfavorably or neutrally.

Rehberg's name was the best known. Fifty-six percent of the voters recognized Rehberg's name favorably, while 21 percent did so unfavorably, with 19 percent neutral. Four percent didn't know him.

Burns' name was second with 45 percent favorable to 24 unfavorable, with 30 percent neutral and 1 percent not recognizing him.

Morrison's name received 22 percent favorable recognition to 7 percent unfavorable, with 40 percent neutral. Thirty-one percent of the voters didn't recognize his name.

Tester had a 14 percent favorable recognition and 4 percent unfavorable, with 21 percent neutral. Sixty-one percent of voters didn't recognize his name.

Kemmis had 8 percent favorable name recognition, 6 percent unfavorable, 17 percent neutral and 69 percent didn't recognize his name.

Lindeen's name drew favorable recognition from 9 percent, unfavorable from 6 percent, with 18 percent neutral. Sixty-seven percent didn't recognize her name.

Political campaigns and advertising, of course, are designed to build up candidates' name recognition with the voters. Most candidates start with little statewide recognition.