Obama, Ryan slam each other while courting Iowa voters - KMSP-TV

For U.S. Rep. Paul Ryan, Monday marked the first day of campaigning alone without Mitt Romney -- but as he courted Iowa voters in Des Moines, President Barack Obama was blasting him over his position on the farm bill at his own campaign stop in Council Bluffs.

"If you happen to see Congressman Ryan, tell him how important this farm bill is for Iowa and our rural communities," Obama urged. "We've got to put politics aside when it comes to doing the right thing."

Ryan was quick to return with jabs of his own after taking to the stage at the Iowa State Fair, saying Obama has failed to provide jobs in the region.

While the race is officially between Obama and former Massachusetts Gov. Mitt Romney, Ryan's views are taking center stage right now. In fact, his presence on the ticket has directed sharp focus on the issue of Medicare.

Obama and Ryan have vastly different approaches. Under Obama, the basic design of the program would stay the same. Ryan, however, takes a much different tactic.

"He introduces a much more dramatic change to the Medicare program," explained Jean Abraham, associate professor at the University of Minnesota's school of Public Health.

Abraham was an economic advisor on health care for both Obama and President George W. Bush, and she says the differences are clear. While Obama would essentially maintain the enormous entitlement program that ensures care for a vulnerable elderly population, Ryan would dramatically change the system to bring costs down in the future.

"It is a more market-based approach in terms of having consumers choose the plan they want and be responsible for additional costs of more expensive programs," she said.

The Obama campaign warns that the subsidy or voucher system would leave millions of seniors without care, and they wasted no time hitting that theme hard on Monday with a web ad criticizing Ryan's plan.

Republicans were quick to return the volley on Medicare, with Republican National Committee Chair Reince Priebus going on 'Meet the Press' on Sunday to say Obama "stole $700 billion from Medicare to fund Obamacare."

Though Abraham knows that politics can often get in the way of action, but she believes time may be running out when it comes to Medicare.

"There's a lot of education that needs to be done to understand how large this program is and what the consequences are of not reforming it," she said.

Romney is currently on a bus tour of Florida, telling Floridians he and his new running mate will revive the housing market and preserve and protect Medicare. He will be in Miami on Monday night.

Currently, there are 49 million people depend on Medicare. That number is expected to rise to 73 million by 2025. Medicare already accounts for 15 percent of the federal budget and 21 percent of health care spending.