Topeka ? Secretary of State Ron Thornburgh made two things clear Thursday: He’s running for a fourth term and he sees the primary race as an indicator of just how much clout conservatives have in the state Republican Party.

“Too late to back out now,” Thornburgh quipped as he signed his paperwork and paid the $1,297 filing fee to face conservative Sen. Kay O’Connor in the Aug. 1 primary.

Democrats say they will have a candidate file before the noon Monday deadline. The primary winner faces the Democratic challenger in the Nov. 7 general election.

“This race is going to be a bellwether race for the primaries in the Republican Party, and it’s going to show my capacity for leadership within the party as well,” Thornburgh said.

For years, the state GOP has been split between moderate and conservative factions. While Thornburgh calls himself a conservative, others view him as more moderate.

“While I am a conservative, Kay is clearly more conservative and tends to have support of individuals from that particular camp,” he said. “So we are going to see just how strong that base is.”

His focus is on the campaign, but Thornburgh also appears to be casting himself as a leader who can help bring the party together.

“I think it’s important for me to step up and provide that leadership,” he said. “It’s important to show that someone who is a traditional conservative has an opportunity to lead the Republican Party of the state of Kansas, and I want to be part of that.”

Since his election in 1994, Thornburgh has won re-election with no primary opponent and weak Democratic opposition in the general elections. In 2002, he won re-election with 65.4 percent of the vote over Democratic and Reform Party opponents.

Thornburgh said this will be his toughest race and that O’Connor is an opponent to be taken seriously.

“You are going to hear Kay say a lot of rather mean and inaccurate things about me from the campaign trail,” he said. “I’m very comfortable letting the voters make the decisions based on my actions versus her words.”

In a separate interview, O’Connor said: “I have no intention of being mean. What I will try to do is expose problems in that office.”

Thornburgh said he’s eager to debate O’Connor, to which she said: “I’m ready. I’m happy to have him ready to debate.”

The state’s chief election officer has been involved in implementing improvements in the election process, including the federal Help Americans Vote Act, which he helped draft.

He also has been involved in developing a statewide voter registration database. It replaces separate but linked databases in the 105 counties.

When O’Connor entered the race in June 2005, she called for an early presidential primary for Kansas. She also complained about moderate GOP leaders trying to open primaries to independent voters. Thornburgh said he’s opposed to open primaries.