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As his Democratic opponents continue to challenge each other for their party's nomination, this Republican candidate with years of experience in Washington has begun running general election advertising before officially receiving the nod in order to maintain a presence in the race and define his candidacy before others can.

John McCain? No, Mike Johanns, former secretary of Agriculture, former Nebraska governor and current candidate for Senate in the state's uncrowded Republican field. Both parties hold their primaries on Tuesday, and Johanns is all but assured of the nomination.

Johanns recently released his first ad of the race, a bio spot replete with images of cowboys and hay-bailing that depicts him as the embodiment of "Nebraska values." In "Proven. Tested. Trusted." (subscription), an announcer claims that Johanns "led us out of a post-9/11 recession" as governor and "changed business as usual at the Department of Agriculture."

Johanns' focus on his experience in President Bush's Cabinet -- as well as his unlikely reference to the Sept. 11 attacks -- suggests that he won't try to distance himself from the past eight years of Republican leadership. Rather, the spot heavily emphasizes experience and nostalgia in an election cycle that Johanns' Democratic opponents are both betting will hinge on change.

One of those opponents, college instructor Scott Kleeb, released a new TV spot this weekend with an eye firmly on the future. In "Time," Kleeb expresses his hope that "Nebraska's best days are still ahead of us," and he proposes to improve health care, invest in renewable energy and deliver tax cuts for working families. Kleeb has struggled to compete with the ad spending of his Democratic opponent, businessman Tony Raimondo, who recently triggered the so-called "millionaire's amendment" after donating nearly half a million dollars to his campaign.

Raimondo has used that fundraising edge to his advantage, releasing two new spots in recent weeks. Two weeks ago, he began airing "Experience" (subscription), touting his "real-world" business credentials and firing shots in both directions. "My Republican opponent is a career politician," he says in the ad. "My Democratic opponent is an academic." (Kleeb's spokesman responded by charging the Raimondo campaign with attacking teachers.) And his latest ad (subscription), released last week, trumpets his recent endorsement by the Omaha World-Herald. Both ads end with Raimondo asserting that he has "the kind of experience needed to change Washington."