Presidential candidates Sens. John McCain (R-Ariz.) and Barack Obama (D-Ill.) engaged in a spirited faceoff Tuesday night in Nashville, Tenn., attacking each other’s positions repeatedly on a broad range of economic and foreign policy issues.

The two at times seemed barely able to conceal their distaste for each other, with Obama impatiently seeking to carve out unalloted time to rebut McCain’s charges and McCain referring to Obama as “that one” and speaking about “Sen. Obama and his cronies and his friends in Washington.”

But the debate was as substantive as it was acerbic. The two presented fundamental differences of philosophy and position on issues like taxes, health care, the budget, spending, energy and foreign policy. Absent from the debate were many of the social issues that often generate the greatest heat between the two parties.

Both candidates professed sympathy for audience members at the town hall-style gathering who might be weary of the sight of two politicians laying into each other. Though both rarely passed up an opportunity to do just that.

Obama repeatedly characterized McCain as eager to reduce taxes for the wealthy – in particular large corporations and Wall Street CEOs – while hoping to continue deregulating everything in sight. McCain charged Obama would raise taxes and embark on a massive spending spree while trying to federalize health care.

On foreign policy, the candidates mostly reprised the arguments of their first debate. McCain said Obama would ineptly announce that he was attacking Pakistan and naively seek to negotiate with countries like Iran, and that he opposed the surge that many believe helped right the situation in Iraq. “Sen. Obama would have brought our troops home in defeat,” McCain said.

Obama said the failure by President Bush to talk to Iraq and North Korea had coincided with the growth in their nuclear programs. He charged that McCain himself had carelessly suggested military action against North Korea and Iran and had been too eager to attack Iraq. Obama emphasized his view that Bush, with McCain’s backing, had launched a misadventure in Iraq while leaving Osama Bin Laden to run loose in the mountains between Afghanistan and Pakistan.

McCain, who trails Obama badly in polling on who can fix the country’s broken economy, sent an unexpected broadside with what appeared to be a major new proposal. McCain said that he would order the Treasury secretary to buy up bad loans and renegotiate the “value of those homes” with homeowners in order to help people keep making their mortgage payments.

Obama said the important thing for the Treasury secretary to do is to understand “that it’s not enough just to help those at the top.”

Asked by moderator Tom Brokaw whom they would choose as Treasury secretary, McCain mentioned the possibility of Meg Whitman, the recently retired CEO of eBay. Obama said Warren Buffett – whom both he and McCain touted as an Obama supporter – might do well in the position.

As expected, both candidates socked Washington hard. Obama positioned himself as the man who can “change the culture in Washington so that lobbyists and special interests aren’t driving the process.” McCain decried “the greed and excess and the cronyism,” presumably of his colleagues in the Senate.

McCain repeatedly stressed his history of working across the aisle with Democrats such as Massachusetts Sen. Edward Kennedy and former Democrat – now Independent – Connecticut Sen. Joe Lieberman. He noted his habit of peeving his own party leadership, something he charged Obama had never done. Obama stressed McCain’s agreement with Bush on a variety of issues.