MASON CITY, Iowa— At Music Man Square here Wednesday night, Sen. Lindsey Graham touted himself as a “very good commander-in-chief” who would do “whatever it takes” to defeat ISIS if he were to win the presidency in 2016.

“I’m running for president because I’m very much worried about where we’re going,” said Graham, R-S.C., who entered the presidential race in June.

Graham, who said the best decision he ever made was going into the Air Force, promised to make national defense the highest priority if he were elected president.

“Homegrown terrorism is what keeps me up at night right now,” Graham said.

Graham also sounded the alarm about the possibility of ISIS terrorists coming from Iraq or Syria to attack America.

“If we don’t defend ourselves over there, they’re coming here,” Graham said. “[I will do] whatever it takes, as long as it takes to defeat these guys.”

But the biggest threat to America, Graham said, is the possibility of Iran obtaining a nuclear weapon. The U.S. and other world powers are currently in negotiations with Iran to contain Tehran’s nuclear program in exchange for sanctions relief.

Switching gears to relate to the crowd (which primarily featured older people) Graham theorized that the amount of money coming into the Medicare and the Social Security system is lower than it used to be because there are less people working.

As the Baby Boomers start retiring, Graham said, more people are taking money out.

“I want to fix the hole in the boat,” Graham said about fixing Social Security for future generations.

Graham stated that the retirement age should be adjusted and the age extended.

Fewer taxes and less regulation can “create an economy where people are competing for your labor,” Graham said.

Finally, Graham, who embraces immigration reform, said that employers should be required to use E-Verify for their employees — which determines if a worker is eligible to work in the country.

He said that legal immigration should be increased, and that the U.S. should work with Mexico to secure the border.