As she chatted up rural South Dakotans, Clinton largely ignored Democratic rival, who continued to gain ground in delegates needed to clinch the nomination and who picked up a sought-after endorsement from former Sen. John Edwards this week.
Clinton noted that President Bush has said he will veto the farm bill, which Congress passed Thursday, and McCain has also said he would veto the bill if he were president.
"They're like two sides of the same coin, and it doesn't amount to much change, does it?" the New York senator said. "I believe saying no to the farm bill is saying no to rural America."
Mr. Bush and McCain both say the bill, which boosts farm subsidies and includes more money for food stamps, is fiscally irresponsible and too generous to wealthy corporate farmers.
"When Bear Stearns needed assistance, we stepped in with a $30 billion package. But when our farmers need help, all they get from Senator McCain and President Bush a veto threat," Clinton said.
Obama applauded passage of the bill in a statement released by his campaign, saying the measure was "far from perfect," but "with so much at stake, we cannot make the perfect the enemy of the good."
The Illinois senator also chided McCain and Mr. Bush for "saying no to Americas farmers and ranchers, no to energy independence, no to the environment, and no to millions of hungry people." Clinton chose South Dakota for her first campaign appearance since her West Virginia win this week, signaling that she is sticking around until the final primaries on June 3 despite call from some Democrats to close ranks behind Obama. The midwestern state, along with Montana, votes that day - the finish line on the primary calendar.
"There are a lot of people who say, 'Well we should just wrap this up,"' Clinton told several hundred South Dakotans while standing on the porch of a fourth-generation family farmhouse in Bath. "Well I've never been impatient with democracy."
While chatting briefly with reporters on her plane enroute to South Dakota, Clinton stuck to small talk - like describing the deer that she occasionally sees in the yard of her Washington home - and refused to say what she thought about Obama winning the endorsement from Edwards, a former rival for the nomination. Both she and Obama had sought his backing.
The former first lady has maintained that her West Virginia triumph over Obama this week bolsters her argument that she would be the stronger nominee to face McCain in key states next fall.
Left with an increasingly unrealistic mathematical path to the nomination, Clinton has turned to philosophical arguments in an attempt to appeal to the party leaders and elected officials known as superdelegates, whose support will likely determine the nominee.
Her host, the Jones family, grows crops and raises a small herd of angus cattle on their farm, situated on a dirt road in the northeast part of the state. The crowd that gathered to hear Clinton listened quietly to her remarks and then spent much of the time asking her about agriculture policy.
Clinton was to make one more stop in South Dakota and then head to California for an evening fundraiser.
Suffering from money woes of more than $20 million in debt and trailing Obama in fundraising power, Clinton met with her finance team and top fundraisers at her Washington home on Wednesday to rally her forces. The message to the group was to remind them that she now has the lead in votes cast thus far throughout the primary season.
Her campaign continues to site a total, however, that includes results from the Florida and Michigan contests that the national Democratic Party has not recognized.