INDIANAPOLIS -- The field is getting crowded ahead of Friday's Republican caucus to choose a substitute candidate for the 7th District congressional seat.

It comes after the party's presumptive candidate, Jon Elrod, said last month he wouldn't take on Democrat André Carson in November, after Carson beat Elrod in a special election in March.

Monday, political newcomer Gabrielle Campo announced her candidacy.

The social worker, who has impressed party leaders as a hard worker and a fresh face, said she would work to harness energy prices, create jobs and improve schools, but said she wouldn't elaborate on her plans until after Friday, 6News' Norman Cox reported.

Campo will face three other potential candidates.

Truck parts salesman Michael Simpson showed up at Campo's rally Monday and said he's running as well.

"My priorities would be lowering prices on everything, putting some kind of freeze on it or something," Simpson told 6News. "We've got to do something, because you can't afford to drive to work, you can't afford to eat, can't afford medicine."

A third candidate -- former city-county councilor Ray Irvin -- told Cox he's also running, and party leaders said Eli Lilly employee Patrick O'Connor will run as well.

The Republican caucus will take place Friday at the Marriott East Hotel on East 21st Street.