Democratic state Sen. Philip C. Jimeno’s surprise decision not to seek re-election to his District 31 seat has politicians from both parties taking a fresh look at the race.

Del. Donald H. Dwyer Jr., a conservative Republican from Glen Burnie, became yesterday the first candidate to step forward since Jimeno announced his retirement last month.

Republicans had labeled the five-term incumbent’s seat as vulnerable. Now party leaders predict the open seat might attract more GOP candidates to run in the district that represents the Marley Neck Peninsula, Pasadena, Gibson Island and Glen Burnie.

At least five Republicans could be on the primary ballot in September. Bryan Simonaire and Charles “Casey” Robison have formally filed to run, according to Chuck Gast, chairman of the county’s Republican Central Committee. Others who have expressed interest include businessman Mike Jacobs and former County Councilman Carl G. “Dutch” Holland.

Since Jimeno said he will step down, GOP leaders also have reached out to Del. John R. Leopold and County Councilman Ronald C. Dillon, both of Pasadena. Both have taken a pass, but party leaders say that others could join the fray.

Erik Robey, vice chairman for the state Republican Party and Dillon’s legislative assistant on the council, said of the possibility of the growing Republican field: “I wouldn’t count anything out until July 3,” the filing deadline for state office.

Del. Joan Cadden, who represents District 31, has been rumored as a potential Democratic candidate, and Democratic leaders are looking at county school board member Edward P. Carey of Brooklyn Park, among others.

State GOP leaders have targeted Jimeno’s seat as one of at least six in the Senate and 14 in the House of Delegates in the November elections.

District 31 has become increasingly conservative in recent election cycles. The district backed Gov. Robert L. Ehrlich Jr. in 2002 by a 2-1 margin.

“The seat lends itself very strongly for a Republican to win. That will strike a lot of interest with many Republican, and Democrats as well,” said Audra Miller, a spokeswoman for the state Republican Party.

Miller added: “Naturally, with the retirement of a politician who has held the seat for a long time, it creates a domino effect. … It creates a heck of an opportunity.”

Dwyer, a firebrand first-term delegate known for his opposition to same-sex marriage, said he has every intention of winning.

“The values that I hold and the conservative views that I represent clearly speak to the majority of the people who live in District 31,” said Dwyer, 48.

Jimeno, of Brooklyn Park, has said that his decision to retire was not motivated by his perceived vulnerability among Republicans, and he expects a fellow Democrat to beat any Republican opponent.

Dwyer acknowledged that he’s running only because Jimeno has stepped aside.

“Why would anyone, from a conservative standpoint, target his voting record?” Dwyer said. “I could not have done it, and I would not have done it.”

Gast said that Jimeno’s impending retirement will motivate “people who have served in various ways in the community and want to prove their mettle.”

Leopold said a number of Republicans have asked him to join the Senate race, but he’s remaining committed to the race for county executive, even though he has not formally filed his intention.

“My focus remains fixed on the county executive race as that office offers the greatest opportunity to help county residents on a daily basis,” said Leopold, who abandoned his campaign for county executive in 1990 to run against Jimeno, infuriating some within his own party. Leopold lost that race.

Dillon said he was inundated with calls and e-mail asking him to run for the Senate, but he said he will seek a second council term.

“At this point in my life, the County Council is where I feel I can make the greatest impact for the citizens of Pasadena, Marley and Gibson Island,” Dillon said in a statement.

No matter the final look of the field, Republicans anticipate a spirited primary race.

Simonaire, a Pasadena resident, had been mounting a campaign for months in anticipation for a fall showdown with Jimeno.

His retirement “kind of put a whole new twist on things,” Simonaire said yesterday. “[Jimeno] was our main target. … Things have changed.”

phill.mcgowan@baltsun.com