(CNN) – Former New Hampshire Sen. Bob Smith is running for Sen. Mel Martinez's Florida seat, according to a report Thursday by the New Hampshire Union Leader.
The Republican, who now lives in Sarasota, Florida, reportedly made the announcement in a letter to supporters and friends.
"'I have agonized over whether to re-enter national politics,'" Smith reportedly wrote in the letter. "'I have concluded that I can no longer sit on the sidelines in this fight for the soul of America.'"
Smith plans to launch a Web site and file the necessary paperwork with the Federal Election Commission soon, according to the report.
Martinez is retiring in 2010. Florida Democrat Rep. Kendrick Meek has announced a run for the open seat while fellow Florida Democrat Alex Sink has announced she is not running. On the Republican side, there is widespread speculation that Gov. Charlie Crist may seek to replace Martinez.