Republican U.S. Rep. Erik Paulsen has netted a Democratic challenger.

Democrat Sharon Sund, who ran for the DFL endorsement in the Third Congressional District in 2012, announced her campaign on Thursday.

National Democrats had eyed Paulsen's seat for possible pick up because it is one of the few seats across the country held by a Republican where President Obama bested Republican Mitt Romney.

In 2012, Obama won 49.5 percent of the vote, to Romney's 48.65 percent in the suburban district. That year, Paulsen won re-election with 58 percent of the vote.

Sund, a DFL activist who has worked in science-related jobs for big Minnesota businesses, said in a release: "I'm running for Congress because Minnesota's families deserve a thriving economy that rewards hard work and innovation."

When she ran in 2012, local DFL activists picked Brian Barnes to run instead and she dropped out.

Paulsen has already built up a considerable war chest to fend off any challengers. According to his most recent campaign finance report, he had $1.7 million cash on hand.