CHICAGO (CBS) — The U.S. Supreme Court has again denied to hear former Gov. Rod Blagojevich’s appeal of his corruption convictions.

The nation’s highest court first rejected Blagojevich’s request in March, but his attorneys filed a petition for rehearing in April. The Supreme Court turned down that petition Monday without comment.

Blagojevich, 59, has spent the past four years in a federal prison in Colorado, after he was sentenced to 14 years for 18 corruption convictions, following two trials. Among the charges against Blagojevich were allegations he tried to sell or trade an appointment to the vacant U.S. Senate seat once held by President Barack Obama, shortly after his election in 2008.

The 7th Circuit Court of Appeals later overturned five of Blagojevich’s 18 convictions, but upheld the remaining counts, and ordered a new sentencing hearing. U.S. District Judge James B. Zagel has scheduled for August 9.

While Blagojevich could get a reduced sentence at a new sentencing hearing, the appeals court noted the evidence against Blagojevich was “overwhelming,” and the 14-year sentence he received was not necessarily excessive for the 13 remaining convictions.

“It is not possible to call 168 months unlawfully high for Blagojevich’s crimes, but the district judge should consider on remand whether it is the most appropriate sentence,” the appeals court wrote last year.

The former governor and his defense team have long proclaimed his innocence, arguing he was participating in legal political horse-trading, and claiming the line between legal and illegal trading of political favors has become blurred, possibly leaving every politician in the U.S. open to prosecution.