Rep. Dean Heller announced his Senate candidacy Tuesday in an e-mail to supporters.

“Your past support has meant a lot me and for this reason I wanted you to be among the first to know that I am running for the United States Senate,” the Nevada Republican wrote in an e-mail obtained by Roll Call and first reported by the Las Vegas Sun.

Heller has long been expected to run for the seat being vacated by scandal-plagued Sen. John Ensign (R), who announced his retirement last week. Heller gives Republicans a strong shot at holding the seat the party worried would be in jeopardy with Ensign on the ticket.

The third-term Congressman has been an elected official since 1990. After four years in the state Assembly, Heller served three terms as secretary of state before being elected to Congress in 2006. Republicans in the state do not expect a wide primary field like the one that developed in 2010, and Heller would be considered the favorite against any Republican opponent that enters the race.

“It has been an honor to serve you and our great state in the House. I hope I can count on your continued support. With your help, we can bring a new conservative majority to the United States Senate,” Heller wrote.

At least four Democrats, including Rep. Shelley Berkley and three statewide elected officials, are considering running. Nevada could be the Democratic Senatorial Campaign Committee’s best shot at picking up a Senate seat.

Democrats are defending 23 Senate seats, while the Republicans are looking to hold 10 seats.

Roll Call Politics rates this race a Tossup.