In a Chicago hearing with the jury absent, U.S. District Judge James Zagel refused to let Blagojevich cite precedents going back to Abraham Lincoln to show his proposed deals to fill Barack Obama's U.S. Senate seat broke no laws, the Chicago Tribune reported.
Prosecutors said Blagojevich was trying to evade the charges and confuse the jury, and Zagel agreed.
On Tuesday Blagojevich acknowledged under cross-examination about a recorded 2008 phone call that he would have been willing to exchange the seat for being named secretary of health and human services.
"Whether there's something I might be able to get as part of that horse trade," Blagojevich testified, "I throw out the position because I wondered if there might be a role for me to help President Obama expand healthcare to every American."
During his third day on the witness stand, the disgraced former governor admitted he spoke "incessantly" about the Senate seat but insisted he always intended to stay within legal bounds, the Chicago Sun-Times reported.
He testified he considered different options -- "good ones, bad ones, stupid ones, ugly ones" -- and discussed all of them with his advisers.