2016 Presidential Candidates React to Obama's Oval Office Address on Terrorism

— -- As President Obama declared in a rare Oval Office address to the nation on Sunday night that last week's mass shooting in San Bernardino, California was an "act of terrorism designed to kill innocent people," Republican presidential candidates were quick to weigh in.

GOP frontrunner Donald Trump appeared to dismiss the speech entirely:

Even before the president spoke to the country, Texas Sen. Ted Cruz, who has seen his poll numbers rise in recent weeks, offered a pre-buttal of sorts.

"The President should resist using terrorist attacks to try to take away the rights of law-abiding Americans," Cruz said in a statement. "Millions of Americans have chosen to protect themselves and their families by purchasing a firearm. This is their right; indeed protecting their families is their obligation. The President should be looking to stop those who would do us harm -- not attempting to take away the constitutional liberties of millions of innocent Americans."

Kentucky Sen. Rand Paul echoed Cruz.

"Disarming more law-abiding citizens will not stop mass murderers and terrorists," he said in a statement after the president's address. "We should be advocating for more concealed carry ability for law-abiding Americans and an end to unconstitutional gun-free zones."

But in his address, Obama did call for stricter gun safety measures.

"Congress should act to make sure no one on a no-fly list is able to buy a gun. What could possibly be the argument for allowing a terrorist suspect to buy a semiautomatic weapon?" Obama asked in his remarks. "This is a matter of national security. We also need to make it harder for people to buy powerful assault weapons like the ones that were used in San Bernardino."

In an interview on Fox News, Florida Sen. Marco Rubio called for a "substantial ground army" to take on the Islamic State.

"You can't just defeat them from an air perspective," he said.

He added: "Nothing we heard in that speech tonight will assuage people's fears."

Ohio Gov. John Kasich was equally blunt.

"The President's strategy is not enough. Without taking the fight to ISIS on the ground, ISIS won’t be defeated," he said in a statement. "Since February I’ve been calling for a coalition to do that. We must stop delaying and do it."

Former Florida Gov. Jeb Bush called for "a war-time Commander-in-Chief who is ready to lead this country."

"We need to remove the self-imposed constraints President Obama has placed on our intelligence community and military, and we need to put in place an aggressive strategy to defeat ISIS and radical Islamic terrorism as I have proposed," Bush said in a statement. "Unfortunately, neither he nor Hillary Clinton has the resolve to put in place such a strategy."