Tech businesswoman Sona Mehring (D), who founded the website CaringBridge to connect sick people with their families, announced her bid Tuesday morning. Former Minnesota House Rep. Mike Obermueller (D), who lost to Kline in 2012, also plans to formally announce his campaign this week, according to the Minneapolis Star-Tribune.

Obermueller held Kline to 54 percent of the vote in 2012 despite being vastly outspent after the district became slightly more Democratic in redistricting — President Obama narrowly carried it. Democrats are hopeful they'll be able to take Kline out this election. He also hasn't ruled out a Senate bid, which would make the seat more likely to flip.

Mehring portrayed herself as a problem-solver in her announcement.

"When a friend was in a time of crisis, I stepped up with an innovative idea to help her solve a problem. That idea became CaringBridge and has helped millions of families get through challenging times," she said in a statement. "Well there is a crisis in Washington and I am ready to step up again with innovative solutions. Instead of helping solve the problem, Congressman Kline has become part of that gridlock and is out of touch with the people he was elected to represent."