After two critically acclaimed seasons, Kelsey Grammer's drama series "Boss" has been canceled, the Starz network announced this week.

Grammer played a ruthless mayor of the city of Chicago in the political drama, which drew rave reviews from many critics and even Oprah Winfrey.

"After much deliberation, we have made the difficult decision to not proceed with [a third season of] 'Boss,'" Starz said in a statement Tuesday. "We remain proud of this award-winning show, its exceptional cast and writers, and are grateful to Kelsey Grammer, [creator] Farhad Safinia and our partners at Lionsgate TV." 

Though the reviews were good, "Boss" suffered from a continual decrease in the ratings, as broken down in a Tuesday report from The Hollywood Reporter.

"The series, which earned a Golden Globe nomination for best drama and an acting win for Grammer, drew 659,000 total viewers to its original October 2011 premiere en route to 1.72 million overall over its first weekend, falling shy of recent scripted launches," The Hollywood Reporter story said. "Season two returned down from its freshman run with a mere 317,000 viewers, ending in October with a season high of 440,000 viewers. The Lionsgate TV drama's sophomore season averaged 937,000 viewers when factoring in multiple premiere weekend airings, down from its first-year average of 1.1 million."

When Grammer appeared earlier this year on "The Tonight Show" with Jay Leno, the actor joked about what might have kept the show from reaching its full potential.

"Now explain something to me, you get a Golden Globe for 'Boss,' but you don't even get an Emmy nomination," Leno said.

Grammer suggested that his political affiliation could perhaps be behind it.

"Yeah, its hard to figure," Grammer said. "It may have to do with several things, honestly, but I think it's possible, I mean, I am a, I'm a declared out of the closet Republican in Hollywood."