Rep. Dean HellerDean HellerSenate passes dozens of bills on way out of town Reid bids farewell to the Senate Reid defends relationship with McConnell in farewell speech MORE (R-Nev.) officially announced Tuesday he's running for retiring Sen. John Ensign's (R-Nev.) seat.

Heller, who's been expected to run, made his announcement in an email to supporters.

In it, the three-term lawmaker talked up his opposition to "reckless government spending."

"As families across Nevada struggle to pay their bills and fight to keep their homes, Barack ObamaBarack ObamaObama urges Congress not to repeal ObamaCare President Obama should curb mass incarceration with clemency DNC applauds Obama investigation into Russian hacking MORE and his beltway allies are proposing record spending that will add to America's job-killing debt from a stratospheric $14 trillion to a staggering $20 trillion," he wrote.

"In 2008, I stood up to former President Bush, then Senator Obama, and Washington special interests and said no to the Wall Street bailout."

The announcement was widely anticipated after Ensign announced March 7 he wouldn't seek reelection in 2012.

Heller is expected to be a formidable candidate. A recent poll from Democratic-leaning Public Policy Polling (PPP) showed Heller starting ahead of every rumored Democratic candidate for the seat.

Democrats see Rep. Shelley Berkley (Nev.) as their best choice but she told The Ballot Box earlier this month she's in no hurry to make a decision.