The three candidates seeking the nomination for the 21st Legislative District seat in the April 22 Democratic primary have big and small policy disagreements, but each of them contends that their election stands to enhance the culture of politics in Harrisburg.

"I bring my life experience and the kind of diversity you haven't seen at the state level in a long time," said Brenda Frazier, who resigned from County Council in February to pursue the seat in the state Legislature.

Ms. Frazier, 66, of Stanton Heights, is running against former Pittsburgh city Councilman Len Bodack Jr., and former Pittsburgh Police Chief Dominic Costa, to replace Lisa Bennington. Ms. Bennington ran as a reform candidate two years ago but the Morningside Democrat decided not to seek re-election.

"I can no longer be a police officer because of my injury, but I feel like I still have a lot to give back to my community. I am a first-time politician and I think I will bring a fresh perspective to the debate in Harrisburg," said Mr. Costa, 56, of the East End.

Shot in the neck during a February 2002 standoff with an armed fugitive in Homewood, Mr. Costa resigned from the Pittsburgh Bureau of Police in 2006.

His experience as a 29-year police officer, Mr. Costa said, gives him a unique perspective that most career politicians in Harrisburg lack.

"My whole career, I learned how to work within government budgets and to talk to the community about important issues like crime and business," said Mr. Costa. His last name, he added, is a known entity in this region.

"Many times when I go knocking on doors, people want to know, which Costa are you?" he said.

Mr. Bodack, 51, of Stanton Heights, not only pointed to his years of service on City Council but also to the spirit of public service that was engendered in him at a young age.

"Public service is something that was stressed in my house when I was growing up. My father served in the state Senate for 24 years, and he was a big role model for me," he said.

Mr. Bodack, a county Democratic Party operative for many years who owned an auto repair shop before his election to City Council, contends his approach to public policy decisions in Harrisburg will be similar to how he worked within the political structure on Grant Street.

"When I was elected to City Council, my first priority was listening to the concerns of my constituents. I worked very hard on quality-of-life issues and crime control and that is the same level of leadership I will take to the Legislature," Mr. Bodack said.

Elected three times to County Council, Ms. Frazier said she will use her influence in Harrisburg to extend some of the key issues she championed in her seven years on council.

"One of the things I want to look at is the relationship between the state and our county board of health," Ms. Frazier said, noting that she supports county Chief Executive Dan Onorato's plan to transfer the county's Air Quality Control program to state control.

"Prior to the [Allegheny County] home rule charter, our board of health got its marching orders from the state. I would like to look at that law now and see what that relationship is like. Some things should be left up to the state, but we have to define the county's role."

Both Mr. Bodack and Mr. Costa concur. They also support a move to reduce the Legislature and a law that would allow entities like Allegheny County to impose a service fee on nonprofit organizations.

All three candidates also support the countywide smoking ban, which Ms. Frazier co-sponsored when she was a County Council member. The smoking ban, which was declared illegal on a county basis, has since been taken up by the Legislature and may become state law.