CHICAGO (CBS) — Congressman Dan Lipinski, a centrist Democrat, pulled out a narrow victory against progressive challenger Marie Newman in Tuesday’s primary, holding a lead of only about 1,600 votes.

While the Associated Press has declared Lipinski the winner, and Newman conceded Wednesday morning in a statement released to the media.

“I entered this race to fight for the rights of the hardworking people in Illinois’ Third District. Our campaign was built on achieving that. Last night, we wanted to make sure that every vote was counted, that every voice was heard. We believed there was a possibility of victory,” she said. “After reviewing the results, we know that we lost by a thin margin. It was a good fight and I am so proud of the grassroots movement we built with hundreds of volunteers and partners all over the district.”

Lipinski has held his seat in the 3rd District in Illinois since 2005, and some Democrats believe he is not in line with his party in Illinois and Washington.

Newman has said Lipinski is too conservative, especially on issues such as abortion, health care, and immigration; and has slammed him for his votes against Obamacare, and the DREAM Act to provide a path to citizenship for some undocumented immigrants.

Tuesday night, Newman said she has forced Lipinski to take more progressive stances during the campaign, including his initial opposition to a $15 minimum wage.

“We have moved him on immigration. We have moved him on health care. I scared the crap out of him on $12 versus $15,” she said.

Lipinski has not declared victory, but told his supporters Tuesday night things were looking good. As for the Democrats who didn’t vote for him, Lipinski said he wants the party to be inclusive.

“I’m saying let’s all come together. For Democrats, I think we need to come together and make it very clear that we are the party for working people,” he said.

In the general election, Lipinski will face Republican Arthur Jones, who ran unopposed in the GOP primary. Jones is a Holocaust denier who openly touts white supremacist and anti-Semitic views, and does not have the support of the Illinois Republican Party.