The U.S. Senate campaign of Maryland Del. Kathy Szeliga (R-Baltimore County) is getting a boost from radio ads aired on her behalf by the conservative group Citizens United, in addition to television commercials her campaign launched last weekend.

With early voting underway before the April 26 primary, Citizens United on Thursday started airing the nearly $25,000 radio spot on Baltimore radio stations WBAL and WCBM. The ad will run through April 25.

Citizens United is best known for a Supreme Court challenge that paved the way to eliminating corporate spending limits in political campaigns.

Szeliga, the minority whip in the House of Delegates, is one of the front-runners in a 14-candidate Republican field that is dominated by political novices.

A recent poll by The Washington Post and the University of Maryland gives her a small lead but found 6 in 10 likely Republican voters have no preference among major candidates in the GOP race.

The polling came before Szeliga started airing commercials to raise her visibility last weekend. The ad shows her riding a motorcycle to Washington and describes her as a mother, grandmother and small business owner who worked with the state’s popular Republican governor, Larry Hogan, to repeal the so-called rain tax and cut tolls.

That ad buy was $120,000 and will continue airing in the Baltimore area through the primary, said campaign spokeswoman Leslie Shedd.

The Citizens United radio ad calls Szeliga a Beltway outsider who “lives in the real world, not the political world.”

It does not mention, however, that she is a former aide to legislators in Annapolis and was elected as a state lawmaker in her own right in 2010. Szeliga is the only state officeholder in the GOP Senate primary. Her leading competitors are trade association executive Chrys Kefalas, former Pentagon official Richard Douglas and tire company owner Joseph Hooe.

U.S. Reps. Chris Van Hollen and Donna F. Edwards are battling in a much costlier and higher-profile contest for the Democratic nomination to succeed retiring Sen. Barbara Mikulski (D).

The Democratic nominee will be favored in the general election, because both Edwards and Van Hollen have higher statewide name recognition than any of the GOP candidates, and registered Democrats outnumber Republicans 2 to 1 in the state.