cory booker*To fill the vacant seat of Senator Frank Lautenberg, D-NJ, who died earlier this week, Newark Mayor Cory Booker announced his candidacy on Saturday

“I’m here today to officially announce my candidacy to be New Jersey’s next United States senator,” Mayor Booker said in a news conference in Trenton, N.J. “Democracy is not a spectator sport, but now as much as in any time, we must bring people together. We must actually get into the complicated difficult messy arena and take on the difficult challenges, work in uncommon ways with conviction and courage.”

Booker praised Lautenberg for his service and leadership in New Jersey and the Senate.

“As a senator and as a citizen, he has been one of the most impactful New Jerseyans. He was truly a giant in the United States Senate. He was a giant for our state and a giant for our nation from his service in World War II to his assiduous work and advocacy in the U.S. Senate,” Cory Booker said of Sen. Lautenberg. “Generations yet unborn will feel the impact of his leadership and contributions.”

Booker, 44, is known for his active Twitter account. He said he’s often been criticized for his tweeting, but he’s not going to stop.

“Too much Twitter from the mayor, too much exposure — there is not a criticism I haven’t heard over the years. I’ve heard it all but, there’s one thing that everyone has to admit about my life as a professional,” he said. “I do not run from challenges. I run towards them.”

Meanwhile, New Jersey Gov. Chris Christie set the date for the special election to fill Lautenberg’s seat for Oct. 16, three weeks before Christie faces re-election himself