TOPEKA ? Incumbent U.S. Sen. Pat Roberts continues to maintain his fundraising advantage over fellow Republican Dr. Milton Wolf in their Kansas primary race.

According to reports filed with the Federal Elections Commission, Roberts raised more than $534,000 from Jan. 1 through March 31, aided by nearly $260,000 from political action committees.

Wolf’s campaign says it raised more than $318,000 during the same period, and that all but $5,050 was contributed by individual donors. Roberts raised $274,000 from individual donors.

Roberts has raised nearly $4 million in his campaign for a fourth term in the Senate. Wolf has raised $587,000, including $30,000 in personal loans to his campaign.