Voters of the 55th District chose Democratic candidate Adam Zemke to fill the party's spot on the November ballot in the race for a seat in the Michigan House of Representatives in Tuesday's primary.

Zemke declared a victory over his opponent, Andrea Brown-Harrison, about 10:15 p.m. Tuesday at a local Democratic party contingent gathering in Ann Arbor after preliminary poll results indicated he was the leader.

Zemke will squaring off against Republican and former Milan Mayor Owen Diaz, as well as Green Party candidate David A. McMahon of Milan in the November general election.

The 55th District seat in the Michigan House is currently filled by Rep. Rick Olson, R-York Township, and is comprised of York, Augusta, Pittsfield and Ann Arbor townships, portions of Ann Arbor and Milan.

Olson did not seek re-election after redistricting changed the political majority of the district from Republican to about 65 percent Democratic.

In a speech made at the gathering at the Heidelberg in Ann Arbor, Zemke, 29, admitted he was nervous going into Tuesday's primary -- though final results showed he drew 61 percent of the vote.

This is not the first time Zemke's name has appeared on a ballot before Washtenaw County voters.

He ran for the 1st District seat on the Washtenaw County Board of Commissioners in 2010 as it was being vacated by Republican Mark Ouimet -- who now serves as a Representative in the Michigan House. Zemke was defeated in the 2010 election by Republican Rob Turner in a 723-vote margin.

"We did all the proper work necessary to run a serious campaign," Zemke said of his 2012 campaign.

He attributed his success in the primary to local Democratic party volunteers and to his manager, Brad O'Conner -- who came from Houston, Tx. to manage Zemke's campaign. The campaign has also made use of a number of volunteers from the college Democrat groups at the University of Michigan and Eastern Michigan University.

Zemke's Democratic challenger Brown-Harrison, a Pittsfield Township trustee, failed to appear at two candidate debates during the primary campaign and has kept a low profile.

She garnered 38 percent of the vote in Tuesday's election. In Augusta Township and portions of York Township, only a few votes separated Zemke from Brown-Harrison.

Planned Parenthood of Michigan and the National Organization of Women both announced their endorsements of Zemke over Brown-Harrison close to the August primary election.

Amy Biolchini covers Washtenaw County, health and environmental issues for AnnArbor.com. Reach her at (734) 623-2552, amybiolchini@annarbor.com or on Twitter.