WASHINGTON - Minutes after a solemn President Obama spelled out his plans to protect Americans from terrorism, Marco Rubio declared that he "may have made things worse." Jeb Bush called the president "weak" and his approach "business as usual."

And Donald Trump declared on Twitter, "We need a new President - FAST!"

Yet beneath their harsh rhetoric lies a fundamental political reality: Few in the Republican Party's 2016 class would break significantly with the Democratic president's approach to combating the Islamic State.

The avalanche of Republican criticism that continued Monday focused on the president's tone, his word choice, and the fine points of his plans - not in most cases the specific policy prescriptions he presented in his address from the Oval Office on Sunday night.

Bush, in an MSNBC interview, twice acknowledged that he agreed with the president's approach in specific areas. Still, he chided Obama's planning for lacking "the intensity that's necessary."

"He needed to persuade people that our fears will subside when we're engaged actively in the destruction of ISIS, and from there you would have a strategy that would be much more comprehensive," Bush said.

He then outlined a plan to strengthen the existing U.S. effort to train local forces and engage Sunni tribal leaders.

Like Obama, most of the GOP's White House hopefuls oppose the use of many U.S. ground troops, preferring instead to send a limited number of special forces to train and support anti-Islamic State forces in the region.

Like Obama, they support an aggressive air campaign to bomb the Islamic State - and target its reliance on oil revenue - across Iraq and Syria.

There are specific differences in some cases - most notably on the GOP's support (shared by Democratic contender Hillary Clinton) for a no-fly zone in Syria.

But on a broader U.S. approach to taking on ISIS in the Middle East, leading Republicans have more in common than not with the president they hope to replace.