Retired Navy Admiral Michael Franken announced Monday he would be seeking the Democratic nomination to unseat Sen. Joni Ernst, R-Iowa.

Franken released a video launching his campaign, highlighting his 40 years of experience in the Navy, and his decision to vote against invading Iraq when given a chance to vote on invasion plans as a Navy representative in the Pentagon in 2002.

“I was trained to not bow to political pressure and to do what’s right,” he said in the video.

He went on to say he believed that Republicans don’t stand up to Donald Trump enough and Democrats in Washington D.C. aren’t doing enough to combat climate change, or stand up to pharmaceuticals or Wall Street.

“Now more than ever, Iowans need a senator who will go against the grain in Washington, to do what’s right for Iowa,” he said.

Three other Democrats are also making a bid for the seat — Kimberly Graham, Theresa Greenfield, and Eddie Mauro.

Ernst, a Republican first elected to the U.S. Senate in 2014, is seeking her second six-year term.