Day 3 in economy debate

Barack Obama holds a roundtable in Chicago today with selected families to highlight his proposals to fight predatory lending -- and, along the way, to bash John McCain.

According to Obama's campaign, he will be joined by consumer advocate Elizabeth Warren to discuss the credit crunch and his plan to help working families climb out of debt.

"We need a president who will look out for the interests of hardworking families, not just their big campaign donors and corporate allies. John McCain fails that test," the campaign said in a memo announcing the event, which replaces one in Cedar Rapids, Iowa, cancelled due to the flooding there.

The memo goes on to accuse the presumptive Republican nominee of repeatedly siding with banking industry lobbyists and against consumers on issues such as transparency on credit card bills, regulations to protect minors from risky credit cards, and changes in bankruptcy law to help families.

McCain, meanwhile, holds an event in Philadelphia and is scheduled to appear at a fund-raiser tonight in Boston, where he will be accompanied by former Massachusetts governor Mitt Romney, who appears to be in the mix to be McCain's running mate.

On NBC's "Today" show this morning, McCain again promoted his idea for a summer gas tax holiday -- suspending the 18.4-cent-a-gallon federal tax until Labor Day. Obama calls that proposal a gimmick, and most economists agree.

McCain, however, is undeterred. "Look what's happened to Americans who are on a fixed income, particularly low-income Americans -- that's why I wanted to give them a little break," he said. "They drive the furthest. They drive the automobiles that use the most gasoline. I wanted to give them a little break for the summer."

In the "Today" interview, McCain also predicted that gas prices, which have topped $4 a gallon for regular unleaded for the first time, won't drop before the November election. "I don't think it's going much lower, and it could go higher," he said. "I don't think so, not when you've got a finite supply, basically, and a cartel controlling it."

While he sidestepped the issue of a windfall profits tax on oil companies -- which Republicans in the US Senate blocked on Tuesday -- he called on the companies to "absolutely" return some profits to consumers. "The point is, oil companies have got to be more participatory in alternate energy, in sharing their profits in a variety of ways, and there is very strong and justifiable emotion about their profits," McCain said.