Republican Mike Johanns has lengthened his lead in the race to become Nebraska’s next United States senator.

The latest Rasmussen Reports telephone survey shows Johanns leading Democrat Scott Kleeb 60 percent to 33 percent.

Last month Johanns led 55 percent to 40 percent. Johanns, a former governor of the state, and Kleeb, a professor and rancher, are seeking to replace Republican Senator Chuck Hagel, who decided not to run for re-election this year.

Johanns leads 59 percent to 33 percent among men in Nebraska and 61 percent to 33 percent among women. He earns support from 84 percent of Republicans in the state, 21 percent of Democrats, and 57 percent of unaffiliated voters. Kleebs support comes from just 69 percent of Democrats, 12 percent of Republicans and 33 percent of unaffiliated voters.

Opinions of the Republican candidate have improved over the past month. Johanns is viewed favorably by 73 percent, up from 65 percent last month. He is viewed unfavorably by 23 percent, down from 27 percent last month.

For Kleeb, those numbers are 50 percent favorable, 35 percent unfavorable. His favorability number is down from 56 percent last month.

Nebraska is one of the few seats the Republican Party can count on to maintain in this year’s senate elections.

Johanns was elected Governor of Nebraska in 1998. Four years later, he was re-elected by a 69 percent to 27 percent margin. Before completing his second term, he went to Washington and served as Secretary of Agriculture.

Kleeb, just 32 years old, ran for Congress from Nebraskas 3rd Congressional District in 2006. He lost that race by ten percentage points but easily won the Democratic Primary last week to represent his party in this years Senate race.

Republican Gov. Dave Heineman could be an asset to Johanns in the election. His approval ratings, though usually high, have improved even more over the past month. He now earns good or excellent ratings from 70 percent of voters in Nebraska, up from 64 percent last month. Just 6 percent say he is doing a poor job as governor.