Reps. Jerry Moran and Todd Tiahrt both put a big Tax Day rally in Kansas City, Kan. on their calendars. After all, in their run for the Republican nomination for the U.S. Senate, the tea party movement is an important group.

Only Tiahrt made it. The reason illuminates perhaps the biggest issue for Kansas’ two senior congressmen in campaigning for higher office — their personalities.

Both are running hard to the right. Yet Tiahrt positions himself as the vocal, aggressive conservative, and Moran’s lower-key style has him battling a perception that he’s a moderate.

Tiahrt went to Kansas City on April 15 for solidarity with the tea party movement. He said the trip showed his willingness to, in a favorite phrase, “ride to the sound of the guns.”

“I’ve been described as a fighter, even confrontational,” he said in a recent interview. “Jerry has been described as folksy.”

Moran stayed in Washington that day to vote against a spending bill he and other Republicans said would increase the nation’s budget deficit. He said voting on such bills will make Washington accountable, which is what the tea party movement wants.

“Yelling or pounding your fist on the table is not a demonstration of being a fighter,” Moran added. “I don’t think you become a fighter by calling yourself a fighter.”

The Moran-Tiahrt race is the biggest one to be settled by the Aug. 3 primary election. They’re seeking the seat held by U.S. Sen. Sam Brownback, a conservative Republican who’s running for governor.

The GOP race has a third declared candidate who’s not perceived as much of a factor. Three Democrats are running, too, but none has the same political clout as Tiahrt or Moran, and in Republican-leaning Kansas, no Democrat has won a Senate race since 1932.

That’s not likely to change this year because, for many Republicans, either Moran or Tiahrt is an acceptable nominee.

Lynda Tyler, organizer of Kansans for Liberty, a Wichita-based, tea party-aligned group, said her household is split. She leans toward Moran, while her husband, Robert, likes Tiahrt.

“I’m glad I don’t have to endorse,” she said. “Let’s play a game of checkers, and whoever wins gets to run and the other stays in the House.”

Moran has a big fundraising advantage, $3.5 million in cash on hand as of March 31, compared to $1.5 million for Tiahrt.

But Tiahrt’s argument that he’ll be more aggressive in opposing President Barack Obama and fellow Democrats resonates with many Republicans.

Tiahrt, who’s represented the 4th District of south-central Kansas since 1995, is backed by Concerned Women for America and the anti-abortion group Kansans for Life. Evangelical leader James Dobson appeared in a recent radio ad.

“They’re both good men,” said Carol Webb, a 59-year-old homemaker from Wichita. “Todd is just a very consistent conservative.”

The argument bothers supporters of Moran, who’s represented the sprawling 1st District of western and central Kansas since 1997. Prominent conservatives like Oklahoma Sen. Tom Coburn and South Carolina Sen. Jim DeMint support him.

“That’s digging pretty deep, to say he’s not a conservative,” said Moran supporter Susan Malone, the 59-year-old manager of a Topeka optometrist’s office.

Moran also has the endorsement of the Kansas Farm Bureau and plays up hundreds of town hall meetings he’s held as a congressman. One television ad emphasizes a down-home theme, saying the food in Kansas isn’t as fancy as in Washington but, “The company’s a whole lot better.”

The 2010 Almanac of American Politics says Moran’s voting record is moderate, while designating Tiahrt’s as “strongly conservative.”

Normally, folksiness works well in Kansas politics. Being described as a moderate hasn’t been a bad thing, while being tagged as a conservative sometimes has spelled trouble.

Democrat Kathleen Sebelius gained a national reputation by wooing disaffected GOP moderates and winning two terms as governor before becoming U.S. health and human services secretary last year.

Kansas has been known for GOP moderates: Emporia newspaper editor William Allen White, Gov. Alf Landon, President Dwight Eisenhower and, more recently, U.S. Sen. Nancy Kassebaum Baker.

Even after abortion opponents became a strong force within the Kansas GOP in the 1990s, moderate Republicans prevented them from imposing as many restrictions on providers as they wanted. When conservatives on the State Board of Education pushed Kansas toward repudiating evolution in science standards for public schools, they inspired a backlash.

Ed Flentje, a professor of public administration at Wichita State University, notes social conservatives have been a force in Republican politics since prohibition was an issue.

They’ve been wedded within the GOP to low-tax, small government conservatives for decades. Threats from strong Democrats push the coalition to the center, said Flentje, co-author of a new book about Kansas politics.

“What if Sebelius were back here running for the seat?” he said of the Senate race.

Meanwhile, policy differences between Tiahrt and Moran sometimes seem subtle.

Moran voted consistently against all proposed versions of President Bush’s No Child Left Behind education reform law in 2001; Tiahrt supported a House GOP version but not the final version. Tiahrt strongly opposes Obama’s policies but voted once for money for the “cash for clunkers” program, which Moran opposed.

The American Conservative Union gives Tiahrt a lifetime rating of more than 95 percent; Moran’s score is almost 92 percent. The U.S. Chamber of Commerce gives Tiahrt a career score of 94, while Moran’s is 91.

“We’re still in the Reagan era,” Flentje said. “Most folks think the voters in the primary are going to be those passionate folks who push the party to the extremes.”