Republican presidential hopeful Mitt Romney hammered Saturday on radical jihadists and Iran's nuclear potential while campaigning in the Little Sioux River Valley, where residents enjoy rodeos, symphonies and county fairs.

Romney said while visiting the campus of a northwest Iowa community college that the new videotaped message from Al Qaeda leader Usama bin Laden is nearly impossible for Americans to understand.

"Who can be so deluded as he is?" Romney said.

Romney told reporters afterward that bin Laden's ideas on Americans being coerced into converting to Islam "are not in line with rational thought."

In the 26-minute video, bin Laden compares the Iraq war to Vietnam, criticizes the Democratic Party for failing to prompt a U.S. pullout from Iraq and encourages Americans to welcome Islam. He does not make any direct warning of an imminent attack.

"The whole radical jihadist movement is extraordinarily misguided and evil and is a form of delusion," Romney said. "I was, in some respects, thankful that he reminded the people of the world what the face of evil looks like."

At the community college, Romney was asked how he would respond to Iran. He said the United States must "tighten the sanctions hard so that the people of Iran understand just what renegades their leaders seem like on the world stage."

Romney said that response also should include the tightening of diplomatic sanctions and indicting Iranian President Mahmoud Ahmadinejad.

"I want to indict him for incitation to genocide," Romney said.

The former Massachusetts governor said he hopes Iran can be persuaded to give up its nuclear ambitions. However, Romney said, if a nuclear weapon from Iran ever found its way "into the hands of terrorists and it's used, we will not just respond to the terrorist, we will respond to the nation who gave the material to the terrorists."

"Regardless of how it might be used in the world, we will act," he said, adding that military action is not just "on the table, it's in our hand."

Romney said the U.S. troop buildup in Iraq is working, but many lawmakers are neither listening nor waiting for a report to Congress by the top U.S. commander in Iraq, Gen. David Petraeus, and U.S. Ambassador Ryan Crocker, which is expected to begin Monday.

"Some of these guys are so anxious to declare defeat that they're not willing to look at the data," Romney told the crowd of about 130 people. Democrats, Romney said, are saying some things that are "dispiriting, disgraceful, obviously discouraging to our troops."

Romney also played to social conservatives repeating his condemnation of same-sex marriages.

He said the recent ruling in Polk County, Iowa, which found the state's ban on gay marriage unconstitutional, was "an attack on the family and on the marriage structure" that points out the need for a federal amendment to the Constitution that defines marriage.

"Civilizations have recognized since the beginning of time ... that the ideal setting for raising a child is where there is a mom and a dad," he said.