Former Secretary of State Colin Powell, who is a Republican, is lashing out at a "dark vein of intolerance" in his own party, which he says is being created by people like former Alaska Gov. Sarah Palin and former New Hampshire Gov. John Sununu who use racial code words and "slave terms" to attack President Barack Obama.

During a Sunday interview, NBC's David Gregory asked Powell why he continued to consider himself a Republican after supporting Obama and taking moderate policy positions.

"I think the Republican Party right now is having an identity problem, and I am still a Republican," Powell explained. "In recent years, there has been a significant shift to the right and we have seen what that shift has produced: two losing presidential campaigns."

"When we see that in one more generation that the minorities of America -- African Americans, Hispanic Americans and Asian Americans -- will be the majority of the country, you can't go around saying, 'We don't want to have a solid immigration policy, we're going to dismiss the 47 percent, we are going to make it hard for the minorities to vote,' as they did in the last election."

"There is also a dark vein of intolerance in some parts of the party," he continued. "They still sort of look down on minorities. How can I evidence that? When I see [Palin] saying that the president is 'shucking and jiving,' that's a racial-era slave term. When I see [Sununu] after the president's first debate, where he didn't do very well, says that the president was 'lazy' -- he didn't say he was slow, he was tired, he didn't do well -- he said he was lazy. Now, it may not mean anything to most Americans, but to those of use who are African Americans, the second word is 'shiftless' and there's a third word that goes along with it."

Powell went on to slam Republicans for "the whole birther movement."

"Why do senior Republican leaders tolerate this kind of discussion within the party?" he wondered. "I think the party has to take a look at itself. It has to take a look at it's responsibilities for health care, it has to take a look at immigration, it has to take a look at those less fortunate than us."

Watch this video from NBC's Meet the Press, broadcast Jan. 13, 2013.