(CNN) -- Sen. Barack Obama on Sunday tried to paint Sen. John McCain as a candidate who is out of touch with the middle class.

Speaking about Friday's presidential debate, Obama accused McCain of not addressing working families.

"We talked about the economy for 40 minutes, and not once did Sen. McCain talk about the struggles that middle class families are facing every day," Obama said at a campaign event in Detroit, Michigan.

The economy took the lead in Friday night's presidential debate, as both candidates highlighted their plans to bring the United States out of what some are describing as the worst financial crisis since the Great Depression.

McCain on Sunday brushed off Obama's latest line of attack, saying he has "bigger things to worry about."

"Who does he think I was talking about when I said 'people on Main Street'? Who did he think I was talking about, about the necessity of helping the American taxpayers and income -- and Americans who are out there working and trying to keep their jobs?" he said on ABC's "This Week."

"I've got bigger things to worry about than that."

The Republican presidential candidate did address "Main Street" in the debate Friday night, saying that "we've got to fix the system" because "Main Street is paying a penalty for the excesses and greed in Washington, D.C., and on Wall Street."

Still, Obama's campaign pointed out that McCain didn't specifically say "middle class," during the debate.

McCain's campaign said Sunday that during the Michigan event, Obama "ignored his [Obama's] record of opposing middle class tax relief, opposing a competitive tax rate, and opposing a plan to incentivize new battery technology." The campaign said Obama's "talk about the middle class is much different than his record."

During the debate, McCain repeatedly said Obama "doesn't understand" key issues the country is facing, but at campaign events this weekend, Obama blasted McCain as the candidate who "doesn't get it." Watch the candidates' plans for the upcoming week »

"The truth is, through 90 minutes of debating, John McCain had a lot to say about me, but he had nothing to say about you. Not once did he say the words 'middle class.' Not once did he talk about working families. I think Sen. McCain just doesn't get it," Obama said Sunday.

The Obama-Biden campaign continues that argument in a new ad that will begin airing nationally on Monday. The ad says when it comes to the economy, McCain "doesn't get it."

"Number of minutes in debate: 90," the announcer says as the words are typed across a blank screen. "Number of times John McCain mentioned the middle class: Zero."

The 30-second spot, "Zero," includes portions of Friday night's debate where Obama suggested McCain has followed President Bush on economic policy. Watch the ad »

A recent CNN/Opinion Research Corporation poll found when it comes to the economy, 47 percent of voters questioned said Republicans are more responsible for the current economic problems, while 24 percent said Democrats are more responsible.

In response to the latest ad, the McCain campaign blasted Obama's tax policy.

"John McCain repeatedly pointed to Sen. Obama's vote in favor of higher taxes on families making just $42,000 a year, and his proposal for $860 billion in lavish new government spending which is a crushing burden on middle class families and the Main Street economy," spokesman Tucker Bounds said in a statement Saturday.

"If he was honest, Barack Obama knows he was unable to debate the merits of supporting higher taxes on the middle class, and bloated government spending during a looming economic crisis -- it's simply indefensible."

The McCain campaign is referring to a June 5, 2008, vote on a resolution (Senate Concurrent Resolution 70) meant to outline the Senate's budget priorities through 2013, but the measure had no practical effect.

According to a CNN review of the resolution, it assumes that most of the 2001 and 2003 tax cuts pushed by President Bush will expire in that time, which McCain says amounts to a tax increase.

Obama and running mate Sen. Joe Biden voted "yes" on the resolution. McCain did not vote.

However, the Democrats offered their own cuts in the 48-page resolution, which called for several tax cuts and breaks, including rolling back the alternative-minimum tax and the so-called "marriage penalty."

According to an analysis by the independent Tax Policy Center, the tax plan Obama has proposed during the campaign would increase taxes in 2009 on the wealthiest 20 percent of households, while offering tax cuts for the other 80 percent.

CNN's Kristi Keck and Emily Sherman contributed to this report.

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