Robert Zadek became the first Illinois Republican to announce he'll run for Sen. Roland Burris's (D) Senate seat over the weekend.

On his campaign website,, Zadek established a platform that focuses on implementing a flat tax.

"I believe that establishing a true flat tax program benefitting individuals and corporations alike and which will immediately balance the federal budget is what needs to be done now," he said.

Burris is currently under investigation by an Illinois state attorney and the Senate Ethics Committee for potentially conflicting testimony about his interactions with indicted former Gov. Rod Blagojevich (D). Burris has yet to say whether he'll seek re-election. He has created a campaign website and legal defense fund, though.

Illinois state Treasurer Alexi Giannoulias (D) has jumped in the race and has raised $1.1 million so far. Rep. Jan Schakowsky (D) is also said to be considering a bid, as is former Commerce Secretary Bill Daley.

Rep. Mark Kirk is considered the GOP's top prospect.

(H/T Senate Guru)