Rep. David Trone of Maryland declared on Thursday that he would run for the open U.S. Senate seat after Sen. Ben Cardin retires.

While in office, Democrat Trone has prioritized issues like opioid addiction, mental health, medical research, and criminal justice reform. The congressman promised to keep pushing those causes in the Senate.

In an interview with The Associated Press, Trone said, “Ben Cardin was a great U.S. senator, and we’re looking forward to following in his enormous shoes.” But there are many issues that Maryland is currently facing, so we need to concentrate on them, starting with the addiction crisis.

Trone, who is the wealthy founder of Total Wine & More liquor stores, spent more than $12 million of his own money on his House race last year. He said it’s too soon to say how much he would spend on a Senate race, but he said using his own fortune means he doesn’t take money from political action committees, corporations or lobbyists.

“And the whole key in that is you make your own decisions,” Trone said. “You can do what’s right for the people of Maryland and not be influenced by anybody.”

Trone is the third candidate to announce a Senate campaign since Cardin said Monday that he would not seek reelection.