Hillary Clinton is trying to sober up her fellow Democrats when it comes to Bernie Sanders.

With an increasingly combative tone, Clinton repeatedly criticized her chief rival for the Democratic presidential nomination during an Iowa swing Thursday. She painted her former U.S. Senate colleague as clueless on foreign policy, politically unrealistic in policy goals and a risky bet for Democrats and Americans alike.

"Senator Sanders doesn't talk very much about foreign policy, but when he does, it raises concerns because sometimes it can sound like he hasn't really thought it through," the former secretary of state said in Indianola. "For example, he suggested we invite Iranian troops into Syria. That is like asking the arsonist to be the firefighter."

The argument had similarities to the line of attack she and her husband, former President Bill Clinton, used against Barack Obama in 2008, when the then-junior senator from Illinois started to overtake her during their historic nomination fight.

Venturing onto turf that's been dominated by Sanders, Clinton took her assault against the senator from Vermont to Iowa college campuses. The sharpened tone, from both Clinton and Sanders, comes just 11 days before the Iowa caucuses that start the nomination calendar.

Sanders, who has been gaining strength in Iowa and holds the lead in New Hampshire, has tried to answer critics who question his foreign policy experience by pointing to Clinton's judgment as a U.S. senator from New York. In 2002, Clinton cast a vote to support the war in Iraq which she has since called a mistake. 

At a stop at Simpson College, where Clinton spoke to an audience of about 500 that skewed more heavily to professors and senior citizens than students, she used a teleprompter. It's a tool she rarely deploys for routine campaign trail appearances and suggested that her campaign wanted to her get her remarks just right, potentially for use in a later television commercial.

Clinton presented Sanders as a wild-eyed idealist who lacks the practicality to get things done in Washington and avoid gridlock. "I'm not interested in ideas that sound good on paper, but will never make it in the real world," she said. "Senator Sanders and I share many of the same goals, but we have different records and different ideas about how to drive progress."

She pointed specifically to Sanders' desire to establish a single-payer health care system, instead of sticking with Obamacare and trying to improve it.

"Rather than build on the progress we've made, he wants to start over from scratch with a whole new system," she said. "In theory, there's a lot to like about some of his ideas. But in theory isn't enough. A president has to deliver in reality."

Mentioning Sander's quarter-century in Congress, Clinton highlighted his failed efforts on health care. "He's introduced his health care plan nine times, but he never got even a single vote in the House, or a single Senate co-sponsor. Not one," she said. "You'll get gridlock and an endless wait for advances that will never come."

Clinton also suggested that Sanders would turn back progress made by Obama. "We just can't take that risk," she said. "Across the board, we have to defend the progress we've made under President Obama and go even further."

Connie Dekoter, 61, a retired utility office worker who attended the event at Simpson College in Indianola, said she'll caucus for Clinton, although her daughter, Kara, is backing Sanders.

"I like him and his ideas, but I don't know if he could beat the Republicans," she said of Sanders. "I don't know if he's as electable as Hillary is."

Clinton is trying to confront Sanders' strength on and around the state's college campuses, where the 74-year-old maverick known for his straight-talk, anti-establishment message has found his greatest support.

Her stops on Thursday are designed to try to blunt some of that. Besides Simpson, south of Des Moines, she's also hitting the University of Iowa in Iowa City for an evening event that will include pop star Demi Lovato.