Seeking to unify his party behind his health care reform plans, President Barack Obama on Thursday met with a group of centrist Democratic Senators and was also scheduled to confer with House Majority Leader Steny Hoyer (D-Md.). The White House meetings came on the heels of Obamas speech to a joint session of Congress on Wednesday evening and were a clear sign that the president recognizes the need to bring wayward Democrats on board with his health care plans, notwithstanding his pointed criticism of Republicans opposition in his speech.The meeting with centrist Democrats was spearheaded by Sens. Evan Bayh (Ind.), Tom Carper (Del.) and Blanche Lincoln (Ark.), who head a working group of moderates, and it even included a few lawmakers whose record is more left-of-center. The meeting lasted for about an hour, and the 17 Senators who participated left the White House without talking to reporters.However, in a prepared statement released following the meeting, Sen. Herb Kohl (D-Wis.), one of the Senators in attendance, suggested that the cost of health care reform and the need to focus on cost as a matter of political messaging were points the group might have raised with Obama.We all understand that we want to move toward universal coverage, but I dont think were focusing enough on costs, Kohl said. Insurance premiums are going up and up and up. This is not sustainable. We need to do a better job of conveying to the American people what were going to do to reduce costs not just to contain costs, but reduce costs and still maintain quality health care, which is totally doable.Those who attended the meeting included Sens. Mark Pryor (Ark.), Mark Warner (Va.), Jeanne Shaheen (N.H.), Mary Landrieu (La.), Claire McCaskill (Mo.), Arlen Specter (Pa.), Mark Begich (Alaska), Mark Udall (Colo.), Bill Nelson (Fla.), Ben Nelson (Neb.), Kay Hagan (N.C.), and Michael Bennet (Colo.), most all of whom represent swing or GOP-leaning conservative states. Sen. Joe Lieberman (ID-Conn.) also participated in the meeting.Meanwhile, Hoyer was set to meet with Obama, according to a source knowledgeable about the meeting. Hoyer is an ally of fiscally conservative Blue Dogs, who are key to Democratic efforts to pass a health care package this year and are responsible for slowing down and then ultimately stopping the House effort to pass a bill on the floor before the August recess.