Obama Warns GOP "Lay Off My Wife"...Tell 'Em Bam!

Sen. Barack Obama ripped into a Republican ad today that targets comments made by his wife, Michelle, and called the GOP tactic "low class" and "detestable."

The senator and his wife discuss the race for the White House. The Illinois senator told "Good Morning America" that he expects hardball tactics from the Republicans if he becomes the Democratic presidential nominee.

"But I also think these folks should lay off my wife," he told "GMA" as his wife chuckled beside him.

Obama told "GMA" that he believes he will win a majority of the Democratic delegates once the votes are counted after Tuesday's primaries in Kentucky and Oregon. Obama is favored in Oregon while rival Sen. Hillary Clinton of New York is expected to win Kentucky.

Obama was careful not to act as if he had already clinched the nomination, but he also tried to present himself as the candidate who will be taking on Republican Sen. John McCain of Arizona in the fall.