Rep. Bennie Thompson, chairman of the House Homeland Security Committee, endorsed Democrat Barack Obama for president Tuesday, saying he favored the Illinois senator’s position on the economy and his ability to excite new voters.

“I looked at the field,” Thompson said on a conference call with Obama and reporters. “Although it’s a good field, I think your message resonates a lot more with the American people.”

Thompson said Obama’s plan for the economy “hits directly at the heart of the problem that we are facing right now in this country.”

Obama said Thompson, a Mississippi Democrat, was an important addition to the coalition of leaders that have joined his campaign.

“He’s been a voice for change who has strengthened our civil rights,” Obama said. “He’s expanded access to health care. He’s made sure all students have the opportunity and resources to succeed in school.”