The last time Rep. Ike Skelton had a competitive election was 1982, not long after fellow Rep. Aaron Schock (R-Ill.) celebrated his first birthday. Missouri had just been redistricted, so the Democrat faced freshman GOP Rep. Wendell Bailey. Since winning that race with 55 percent of the vote, Skelton has never dropped below 60 percent in a general election.

But in a Republican year, Skelton, 78, has cause for concern. Sen. John McCain (R-Ariz.) carried the 4th district with 61 percent of the vote in the 2008 presidential race. The district has elected almost all Republicans to the state Legislature. Regardless of the Republican candidate, this was likely to be a marquee race in 2010.

Former state Rep. Vicky Hartzler won last week’s GOP primary, defeating her closest competitor, state Sen. Bill Stouffer, 41 percent to 30 percent. Stouffer and Hartzler tangled in the last weeks of the campaign over votes for tax increases in the state Legislature.

Hartzler, 49, served in the state House from 1994 to 2000. In 2004, she served as statewide spokeswoman for the Missouri Coalition to Protect Marriage, which opposed same-sex marriage, and in 2005, then-Gov. Matt Blunt (R) appointed her chairwoman of a council that assisted women in business. Hartzler and her husband live on a farm near Harrisonville and sell farming equipment. She’s the author of “Running God’s Way: Step by Step to a Successful Political Campaign.”

Hartzler said drawing a distinction between her and the 17-term Congressman will be easy.

“The most important vote he cast is for Speaker, and he cast our vote for Nancy Pelosi,” she said in a phone interview after her primary win.

Hartzler said she plans to focus on economic issues in the campaign, but she’ll also contrast her socially conservative values with Skelton’s. Though neither supports repeal of “don’t ask, don’t tell,” Hartzler said Skelton should have done more to support it. She also named Skelton’s vote in favor of a hate-crimes bill as a difference. Both oppose abortion rights.

Hartzler is likely to bring the full force of national Republican support into the race. Though a decision has not yet been made, the candidate said she has talked to the National Republican Congressional Committee about moving onto its “Young Guns” program for promising challengers.

Randall Gutermuth, vice president at the Republican polling firm American Viewpoint, conducted a preliminary survey for the Hartzler campaign at the end of June. He declined to share the poll but said he found bad news for Skelton: Not only did Pelosi have an unfavorable rating of 52 percent and favorable rating of 7 percent in the district, but only 42 percent of respondents said they would definitely or probably vote to re-elect Skelton.

“If Ike Skelton wasn’t running and it was an open seat, I doubt the Democrats would even play in this district,” he said.

Yet in 34 years in the House, Skelton has built up some formidable strengths.

“When you’ve got someone who’s the chairman of the House Armed Services Committee standing up for a Congressional district that has two major military installations that are extraordinarily important to the economics of the district and you’ve got somebody on the other side who doesn’t have the same type of record, I think people in the district will recognize that,” said Jason Rauch, Skelton’s campaign manager.

And without a competitive primary of his own, the incumbent has had time to build up an equally formidable war chest: By the end of June, Skelton had raised $1.9 million and had $1.4 million on hand. He has already aired two TV ads in the Springfield and Jefferson City-Columbia markets touting his legislative accomplishments on behalf of the district’s biggest military bases, Fort Leonard Wood and Whiteman Air Force Base.

The ads telegraph Skelton’s intent to make his work on military issues one of the main themes of his campaign.

“Ike Skelton’s always been pro-defense and pro-military. He supports our troops, and just this year he fought to protect Tricare, the health program soldiers and vets rely on,” Missouri veteran George Fairfax said in the first ad.

Even if Skelton defeats Hartzler, this is unlikely to be his last tough race: Missouri may lose a seat in reapportionment next cycle, potentially setting up another Member vs. Member contest 30 years after 1982. That is, if Skelton runs again.