The story

Arlen Specter, the longtime Republican senator who switched parties Tuesday, admitted Wednesday the move was driven partly by a desire to keep his seat.

The senator, who has represented Pennsylvania in the upper chamber since 1980, said he was "anxious" to stay in the Senate -- and he did not want to face a Republican primary in order to keep his seat next year.

"I was unwilling to subject my 29-year record in the U.S. Senate to the Pennsylvania Republican primary electorate," he said. "But I am pleased to run in the primary on the Democratic ticket and am ready, willing and anxious to take on all comers in the general election." Read full article »

CNN's Alan Silverleib and Deirdre Walsh contributed to this report.

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