Republican U.S. Senate nominee Bob Schaffer took to the offensive against Democrat Mark Udall on the economy and other issues as the two faced off on "Meet the Press" on Sunday.

Schaffer, a U.S. representative from 1998 until 2002, said Udall and other House Democrats helped create the Wall Street crisis by weakening oversight of troubled mortgage houses Fannie Mae and Freddie Mac.

"There's lots of people in Washington who can't make a prudent decision or make a tough call on what's really a priority for the country," Schaffer said. "But when I was there (in Congress), I did. I've been back in the private sector paying these taxes and generating revenue for the country and helping to create jobs, and when I come back to Washington, I'll take all that experience with me and do it in a way that Mark, you never did in the 10 years you've been there."

Udall hit back, saying the crisis came "because of policies of Congress in the '90s, (and) in the early part of this decade."

"For you to sit here and suggest that somehow you're immune from any of the criticism or any of the blame for the straits we find ourselves in is laughable," Udall told Schaffer. "The financial system meltdown, (the) middle class being choked, no energy policy, a war with no end, CEOs getting welfare -- this is a direct example and the direct result of what you did and what you supported when you were in Congress."

Schaffer defended earlier comments he had made in which he said "the federal government is raking in a bunch of cash right now on the backs of energy producers."

But he backed off slightly from his earlier remarks that energy companies' marginal profit of 8 percent was "modest" compared to "insurance companies or banks or other industries."

"An 8 percent marginal profit is not too bad in the American context today," Schaffer said Sunday.

Schaffer said he would "dramatically" change America's energy policy, to which Udall replied, "That's laughable."

"Congressman Schaffer's an oil and gas executive," Udall said. "Of course he's going to take the side of the oil and gas industry."

Under pressure from moderator Tom Brokaw, Udall also said that "it would be helpful" if embattled U.S. Rep. Charles Rangel (D-N.Y.) stepped down as chairman of the House Ways and Means Committee, though he said "it's (Rangel's) decision whether he steps down or not."