America's porous southern border has long been one of Bill O'Reilly's pet peeves, and the outrage over Arizona's immigration law has stoked his fury. After devoting his Talking Point Memo to a blistering attack on Presidents Clinton, Bush and Obama for failing to secure the Mexican border, O'Reilly unloaded on a longtime ally: Republican strategist Karl Rove.

The Fox News host had little patience for Rove's defense of Bush-era efforts to protect the border. Visibly irate, O'Reilly pummeled the Bush administration for being "slow" and employing a virtual fence that amounted to "$50 million wasted." When Rove tried to defend himself, O'Reilly cut him off in a vintage display.

O'REILLY: You were slow.

ROVE: No.

O'REILLY: It took me five year to pound you guys into sending the Guard to the border. After five years of me pounding you, you did it. That was far too slow.

ROVE: Bill--

O'REILLY: Secondly, secondly--

ROVE: Bill, I hate to tell you, Bill, I hate to tell you--

O'REILLY: Hold it, hold it. Let me get mine--

ROVE: --but governors had something--

O'REILLY: I let you have yours. Let me have mine. Let me have mine.

ROVE: All right.

O'REILLY: You were slow to get the Guard to the border. That's a fact.