ELK GROVE VILLAGE, Ill. (AP) Making a play for middle-class voters, Republican presidential candidate Mitt Romney sought Tuesday to elevate welfare reform as a campaign issue, accusing President Barack Obama of encouraging a "culture of dependency."

Campaigning near the president's hometown of Chicago, Romney suggested Obama had dismantled the 1996 welfare reform overhaul signed into law by President Bill Clinton. Romney said that, if elected, he would make sure welfare recipients are required to work.

"We will end a culture of dependency and restore a culture of good hard work," Romney said.

White House spokesman Jay Carney blasted Romney's assertions as "categorically false and blatantly dishonest."

Romney countered with his own charges of dishonesty by the president. In an interview with Fox News, Romney said Obama was "saying things that are not accurate" about the Republican's tax proposals.

At a fundraiser Monday night, Obama called Romney's tax plan "Romney Hood" because he says it would give tax breaks to the wealthiest Americans while forcing the middle class to pay up to $2,000 a year in additional taxes. Romney referred to Obama's campaign appearance as "Obama-loney", rhyming it with "baloney."

The Romney campaign pressed the welfare issue in a new ad criticizing Obama for his decision last month to change welfare requirements. The White House said Obama wanted to give states the flexibility they had been seeking to tailor the program to their needs.

But some conservatives fear the increased latitude could allow states to get around the work requirements, which were a key element of the welfare overhaul under Clinton.

Romney was among several Republican governors who signed a letter in 2005 asking for more "waiver authority." Romney is a former Massachusetts governor.

His campaign sees Obama's decision on welfare as an opportunity to argue that the president is a liberal who wants to give the poor a free pass at the expense of the middle class.

"His policies will take America backward back to the discredited liberalism of a bygone era where bigger government programs and bigger government checks were the answer to every problem, and accountability was not on the agenda," said Lanhee Chen, Romney's policy director.

The welfare push also aims to drive a wedge between Obama and Clinton, who has taken on an increasingly prominent role in the president's re-election bid. The Obama campaign, seeking to take advantage of Clinton's popularity and strong economic record while in office, gave Clinton a high-profile, prime-time speaking role at the Democratic convention, which starts Sept. 4.

Clinton is also helping the Democratic-leaning super PAC Priorities USA Action boost its sluggish fundraising. The former president will host an event for the group in New York next week to help it raise money.

Romney praised Clinton's welfare reforms as "a great accomplishment" that encouraged people to work.

Democrats made their own appeal to middle-class voters Tuesday with a new ad from Priorities USA Action that targets Romney's business record at Bain Capital, the private equity fund he ran. The ad features a former employee at GST Steel who lost his job and health insurance when Bain closed the Kansas-based steel plant in 2001. The man says he doesn't think Romney "understands what he's done to people's lives" by closing the plant.

The ad is the fifth in a series by the group targeting Romney's business record, the centerpiece of the presumptive Republican nominee's campaign. The spot is running in five battleground states: Florida, Ohio, Iowa, Virginia and Pennsylvania.

The candidates were to turn their focus on battleground state voters later in the week.

Obama will embark on a two-day swing through Colorado starting Wednesday. A campaign official said the president would be introduced during an event in Denver by Sandra Fluke. The Georgetown University graduate student gained notoriety earlier this year when conservative talk show host Rush Limbaugh called her a slut for backing an element in Obama's health care overhaul that requires health insurance companies to cover contraception.

Fluke's appearance at the Denver rally underscores the Obama campaign's focus in Colorado on female voters, who could determine the outcome of the presidential race in the state.

Romney, who is narrowing in on his vice presidential pick, will launch a four-state bus tour later this week that will take him to Virginia, North Carolina, Florida and Ohio.

Meanwhile, Republicans announced more speakers for the convention opening Aug. 27 in Tampa, Fla., where Romney will officially accept the GOP nomination. Former Pennsylvania Sen. Rick Santorum, who challenged Romney during the primaries, former Florida Gov. Jeb Bush and Kentucky Sen. Rand Paul are among them.

Democrats announced Tuesday that former President Jimmy Carter will tape a video message that will be aired in prime time at their convention.