Paul Hackett (search), the Democratic veteran of the Iraq war who narrowly lost a special election in a heavily Republican congressional district in August, made his official entry into a U.S. Senate race Monday.

He faces a tough Democratic primary with Rep. Sherrod Brown in the race for the nomination to challenge second-term Republican incumbent Sen. Mike DeWine (search) next year.

Hackett's only political experience is a stint as a small-city councilman.

"I'm asking all the people of this great state, regardless of political affiliation, to consider my message and to consider joining me in the fight to take back our government from the career politicians and their special interest support groups who have hijacked our government," he said as he announced his campaign at his home in suburban Indian Hill.

Hackett decided to run for Congress earlier this year after completing a seven-month tour of duty in Iraq as a Marine reservist. That special election in southern Ohio's seven-county 2nd District was to replace Rep. Rob Portman, who left his seat to become the U.S. trade representative.

Hackett won the Democratic nomination, then battled Republican Jean Schmidt, a former state legislator, in a campaign in which he linked her to embattled Republican Gov. Bob Taft while sharply criticizing President Bush's handling of the war.

Schmidt won on Aug. 2 with 52 percent of the vote, though Portman had consistently won re-election in the district with more than 70 percent and Bush had carried it in 2004 with 64 percent.

Hackett's strong showing in a state that was a pivotal presidential battleground solidified the attorney as a likely 2006 candidate for Congress or statewide office.

After Hackett decided to oppose DeWine, Hackett was irked when Brown, with three decades of elective politics behind him, decided he also would run.

Brown, a former state legislator and Ohio secretary of state, is in his seventh congressional term, representing northeastern Ohio's 13th District. He's expected to officially launch his Senate race in early November.

Brown said Monday he initially didn't plan to run because of family reasons, but changed his mind with his family's encouragement. He said he wasn't expecting the race for the May 2 primary to damage his chances of defeating DeWine in the general election.

"I've had primaries before," Brown said. "It makes me a stronger candidate."