Will Ferrell's 'America' spikes HBO's ratings

"Will Ferrell: You're Welcome America -- A Final Night with George W. Bush" drew HBO's largest audience for a comedy special in five years.

"America" drew 2.3 million viewers, the most since "Chris Rock: Never Scared" in 2004.

Saturday night's spoof of the Bush years was followed by a strong Sunday evening, with "Big Love" having its second-largest audience of the season (2.3 million viewers) and "Eastbound & Down" garnering its biggest viewership yet (950,000 viewers). "Eastbound" is also up 41% at this point compared with its lackluster season premiere.

HBO also put pressure on competitors, with Showtime's "United States of Tara" hitting a season low. (550,000 viewers)