Washington (CNN) - Soon after Don Bivens launched his Arizona Senate bid Monday, the former Arizona Democratic Party Chairman took his first hit from GOP opponent Rep. Jeff Flake.
"If the Democrats indeed put forth a liberal lawyer and former Party Chairman, the voters will have a clear choice come November," Flake said in a statement.
Bivens is the first Democrat to announce a run for the Senate seat, soon to be vacated by retiring GOP Senate Minority Whip Jon Kyl, who's now in his third term. With Kyl leaving, the open Senate race is expected to be a closely-watched contest in 2012.
Bivens announced his run Monday with a video on his campaign website.
"We can't keep sending the same folks back to Washington and expect a different result," Bivens said.
- CNN's Martina Stewart contributed to this report.