Downtown Ald. Brendan Reilly (42nd) is making a bid to boost his influence within the Democratic Party by running for a second office, he announced in an email to his supporters Monday afternoon.

Reilly is running for the office of 42nd Ward Democratic Committeeman, a position that would entrench him as the party’s official representative in the ward. The current committeeman, John Corrigan, is a longtime friend of Reilly’s who was elected to the seat in 2008. He’s stepping down and has endorsed Reilly to replace him next year.

On top of his aldermanic responsibilities, Reilly would be responsible for putting out the party’s message in the ward and getting out the vote on Election Day. Some committeemen also dole out additional community services, though the details change from ward to ward.

How much more political power the new position might afford Reilly is unclear, but previous politicians to hold the seat were among Chicago’s most influential in the Democratic machine.

For more than four decades, the 42nd Ward committeeman’s post was held by party insider George Dunne, the clout-rich longtime head of the Cook County Board and chairman of the Cook County Democratic Party. Though Dunne gave those positions up in the early 1990s, he held onto the committeeman’s seat until he stepped down in 2003.

Former 42nd Ward alderman Burton Natarus, who had served alongside Dunne for nearly 30 years, then took over the position and held it until shortly after he was unseated as alderman by Reilly in 2007.

Natarus said he didn’t gain any more clout by becoming committeeman, simply because he had already been in politics for so long by the time he took the post. But Reilly, a relatively fresh face in the City Council and having just been elected to his second term, could gain more influence by becoming committeeman, Natarus said.

“I think it gives you more authority, and it also helps you solidify your own organization,” Natarus said. “What you can do then is call your own organization the Democratic organization. Now what he can do is infuse into the Democratic Party his own people. … It promotes him within the party.”

Corrigan, an attorney and an experienced organizer in the Democratic Party, said he decided not to run for a second term as committeeman because of his young family.

“It’s been tough to do the work, combined with the fact that my wife and I just had a 1-year-old. It’s just been tough to build the organization further in the ward,” Corrigan said. “I’m turning the reins over to a very competent and skilled alderman.”

Reilly had expressed some interest in holding the seat — though Corrigan said he couldn’t recall who brought it up first.

Right off the bat, Corrigan said Reilly should have a leg up on him in the clout department.

“He’s going to have a lot of advantages just because he’s working in the city all the time, and that’s a real big one,” Corrigan said. “I think that when you’re around 24/7 when you’re an alderman, and you need to do some organizing on the political side, it’s a lot less planning. You can have impromptu meetings and things along those lines.”

Reilly still has to be elected to the position. It’ll be on the ballot in next spring’s Democratic primary election.