(CNN) -- Sens. Barack Obama and Hillary Clinton hit each other hard Monday, a day before contests in North Carolina and Indiana that could break the deadlock over who will be the Democratic nominee for president.
Sen. Hillary Clinton is accusing Sen. Barack Obama of being out of touch with the middle class.
The Democratic rivals traded shots over Clinton's proposal that the government do away with the federal gas tax for the summer and make up the budget shortfall by taxing what she calls oil companies' "windfall profits."
Obama has dismissed the proposal, saying it's unlikely to help consumers or to become law, prompting Clinton to accuse him of being out of touch with "the hard-working American consumer and the middle class."
"I talk to people who are telling me they're literally sick at their stomach when they pull into the gas station trying to pay these gas bills. ... I guess I'm just feeling more of the concerns that people have, and they want relief," she said on CNN's "American Morning" on Monday.
Obama denied being insensitive.
"I understand how badly people are hurting. If we're serious about helping them, let's provide them some relief, but let's not pretend that we're doing something by suggesting a gas tax holiday that will not be paid for and frankly, it is very unlikely that you'd see President George Bush sign," he said in a separate interview on the same program. Watch what Obama says about the gas tax holiday »
The two also exchanged accusations over Clinton's recent comment that the United States could "obliterate" Iran if the Islamic state were to attack Israel with nuclear weapons.
Clinton said she intended to communicate that "there would be a very, very high price to pay" if Iran attacked the U.S. ally, but that "nobody wants to go to war with Iran." She refused to say whether she would order a nuclear response. Watch what Clinton says about Iran »
Obama is ahead of Clinton in the North Carolina polls, while CNN's latest poll of polls suggests Clinton is up in Indiana after the two have long been tied there.
In North Carolina, Obama leads Clinton 50-42 percent, with 8 percent of Democratic primary voters saying they are unsure who they will vote for. The North Carolina Democratic "poll of polls" consists of three surveys: Zogby (May 3-4), ARG (April 30-May 1) and Research 2000 (April 29-30).
In Indiana, Clinton leads Obama 48-44 percent, with 8 percent of voters saying they are unsure. The Indiana Democratic "poll of polls" consists of three surveys: Suffolk University (May 3-4), Zogby (May 3-4) and ARG (April 30-May 1). Watch an analysis of the latest polls »
Obama is hanging on to a slim but significant lead among the delegates who determine which candidate will face presumptive Republican nominee Sen. John McCain in November.
Following a weekend vote in Guam where Obama won by seven votes, he has the backing of 1,736 delegates to Clinton's 1,599.
A candidate needs 2,205 delegates to clinch the nomination. There are 115 pledged delegates at stake in North Carolina and 72 up for grabs in Indiana.
Superdelegate Kalyn Free announced Monday she is endorsing Obama. Free is the president of the Indigenous Democratic Network, INDN's List. The group works to train Native American candidates and mobilize voters in the Native American community.
Campaigning Monday in Greenville, Clinton expressed confidence that the Democrats would be able to come together despite the drawn out nominating process.
"Once we have a nominee, we're going to close ranks and have a unified party because the differences between us as Democrats pale in comparison to the differences we have with Sen. McCain and the Republicans," she said.
Following her event in Greenville, Clinton was scheduled to campaign in High Point before traveling back to Indiana.
Obama started his day visiting with construction workers in Evansville, Indiana. He was scheduled to campaign in North Carolina before returning to Indiana for a rally in Indianapolis. E-mail to a friend