Topeka ? U.S. Sen. Pat Roberts filed for re-election Wednesday and said he will conduct an “aggressive campaign,” although it appears he won’t face any major opposition this year.

The Republican from Dodge City announced his plans to seek a second, six-year term when he filed his papers with the Secretary of State’s Office and paid his $1,451 filing fee.

Republican leaders have said they don’t expect any major primary opponent for Roberts in the Aug. 6 primary. Democrats still are searching for a Senate candidate in the Nov. 5 election.

Roberts told reporters he wasn’t taking his re-election bid for granted.

“I think anytime you put your name on the ballot and ask for the public trust, you’ve got to earn it,” he said.

Roberts first was elected to the Senate in 1996, filling the vacancy created by the retirement of Nancy Kassebaum Baker. Before that, he was the 1st District congressman for 16 years.

The senator can expect at least one opponent in November. George H. Cook, of Mission, said he plans to file as a Reform Party candidate.