(CBS News) In the race for the White House, the two candidates and their running mates are out on the campaign trail. President Barack Obama, Vice President Joe Biden, Mitt Romney and Paul Ryan, will all be stumping Tuesday in key states.
The president is continuing a three-day bus tour of Iowa, and he's lost no time in criticizing his rival's vice-presidential pick. The president arrived at the Iowa State Fair just five hours after Paul Ryan departed. Mr. Obama took pictures with supporters and tried the pork chops. It was the end of day one of his three-day bus tour of Iowa, the battleground state that launched his presidential aspirations four years ago with a win in the Iowa caucuses.
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On Monday, he visited a family farm in drought-stricken Missouri Valley, Iowa, and announced the government's plan to buy $170 million worth of agricultural products from struggling farmers and ranchers.
Mr. Obama said he and his administration, "understand this won't solve the problem. We can't make it rain. But this will help families like the McIntoshes in states across the country."
But his campaign's primary focus right now is on defining Romney's new running mate who is still unknown to many undecided voters.
"My opponent chose as his running mate the ideological leader of Republicans in Congress," Mr. Obama said, "and I've gotten to know Congressman Ryan. He's a good man. He's a family man. He's a very articulate spokesman for Governor Romney's vision. The problem is, it's the wrong vision for America."
Both the president and vice president are painting Ryan as an inspiration for the Tea Party, an ideologue whose proposals for radically smaller government would hurt the poor and give tax cuts to the rich.
"They called, when they talked about their plan - not just their budget plan, but their plan across the board - they called it gutsy," said Biden. "Now look, what's gutsy about giving millionaires another tax break?"
First lady Michelle Obama, visiting Los Angeles, was asked if she was surprised by the choice of Ryan by Jay Leno of "The Tonight Show."
"You know," replied the first lady, "I...haven't spent much time thinking about that and don't know Ryan that well, but we welcome them to the campaign."
Obama campaign officials conceded that Ryan has an engaging personality and is a tough debater who won't back down. But even as they attack him, they continue to insist that he is not nearly as important as the man at the top of the ticket - Romney.
For more on this story, watch Nancy Cordes' full report in the video above.