"It's a valid question, not because we're talking about history; we're talking about the Middle East, where history repeats itself," Paul said, before asking whether the instability in the nation allowed
Bush, who spoke before Paul, did not directly address his own remarks about Iraq, but did mention his brother, former President George W. Bush, who launched the war.
"Some of you may know W's my brother," Bush said. "I'm proud of that too. Whether people don't like that or not, they're just going to have to get used to it."
"If I'm president of the United States and you're thinking about joining Al Qaeda … I'm not going to call a judge" to get a warrant, Graham said. "I'm going to call a drone and we will kill you."
The candidates — three of whom have formally announced their intention to run for president — made their remarks at the state GOP's annual Lincoln Day fundraiser dinner, addressing 1,300 of the party's most committed activists whose support and organizational skills could be crucial to winning Iowa's first-in-the-nation caucuses.
Several candidates laced their speeches with references to the Hawkeye State. Wisconsin Gov.
Rick Perry, who was a farmer before he became Texas' governor, spoke about the rows of corn he drove by earlier in the day.
Former Pennsylvania Sen.
Most of the speakers avoided criticizing their potential rivals, instead touting their biographies and records and denouncing Obama's policies domestically and abroad. National security and the specter of Islamic State threatening Americans were a constant in the remarks.
"I get awfully frustrated when I hear the president draws a line in the sand and allows people to cross it," Walker said. "A president who called, just last year, [Islamic State] the JV squad, who called Yemen a success story, who still calls today Iran a place we can do business with. Well, I've got news for you, Mr. President. Once and for all, we need a commander in chief that calls it what it is — and that is, radical Islamic terrorism is a threat to us all, and we need to act on it."
Carson noted that Lincoln had little time in elected office before he assumed the presidency.
"Some people seem to think many years of political experience are necessary in order to be able to think and to have courage. And I'm not sure that that's true," Carson said.
Fiorina, who has relished criticizing Clinton, said she had answered 372 questions on the record since entering the race this month. The Democratic candidate, she said, had answered eight, including one about whether Fiorina was criticizing Clinton because she is a woman.
"I'm criticizing Hillary Clinton because I come from a world where a title is just a title and talk is just talk and actions speak louder than words, and people want to know what is your track record and what have you actually accomplished," said Fiorina, who unsuccessfully ran for Senate in California in 2010 after being fired by Hewlett-Packard.
After the meal — beef tenderloin, asparagus and cheesecake — the candidates held receptions for the activists. Walker served Wisconsin cheddar cheese, Jindal gave out bandannas similar to the one worn by the leader of television's "Duck Dynasty" family, Trump posed for photos, and Carson offered root-beer floats.