Boston (CNN) - The stakes are high for Democrats in Massachusetts, CNN Chief National Correspondent John King reports.
"This was Teddy Kennedy's seat for more than 46 years," King said Tuesday shortly after polls closed.
Kennedy was "perhaps the best known liberal in the United States. Just 14 months ago, President Obama carried this state by more than 25 points over John McCain. And yet the people of Massachusetts could send a message tonight by sending a Republican to Washington to replace Ted Kennedy."
Republican Scott Brown has campaigned on the theme of being the 41st vote Senate Republicans need to scuttle Democratic plans to pass health care reform legislation.
"It has been more than 30 years since there has been a Republican United States senator from the state of Massachusetts," King said. Republicans "believe that in just a few hours they may have a victorious candidate who will reshape politics not only in this state's politics but the dynamics in Congress and, without a doubt, the dynamic in this early month – the first month of the midterm election year."