JEB BUSH: Here's the plan to jump-start my campaign, defeat Donald Trump, and win the GOP nomination

Jeb Bush
Jeb Bush

(Graham Flanagan/Business Insider)
Jeb Bush high-fives a voter in New Hampshire.

Milford, New Hampshire —

These days, the signature exclamation mark next to Jeb Bush's name could be more like a hazard symbol.

In front of a standing-room-only crowd here for a town-hall event on Thursday, the former Florida governor's opening pitch was simple: Who's going to keep you safe?

"The world has been turned upside down," Bush told the attendees. "We have this existential threat now that people sense. And because of that, we're getting more serious about who we're going to pick."

Amid a lag in the polls for months upon months, this is the crux of Bush's bet: As the presidential campaign becomes more dictated by foreign-policy and national-security events, the "serious" candidate with a history of executive-leadership experience stands to benefit.

Not real-estate mogul Donald Trump, whose divisive political campaign led him to scrap a plan to visit Israel, America's closest Middle East ally later this month.

Not Ted Cruz, a first-term senator. (Bush criticized Cruz by name on Thursday for voting to curb the National Security Agency's surveillance programs. "I hope he has a change of heart," Bush said.)

Not Hillary Clinton, who he argues had her chance to shape the world as US secretary of state and didn't live up to the task.

"I think now is the time, more recently than maybe in 20 or 30 years, because of the failure of this White House — foreign policy and national security was way down on the list of concerns and priorities," said Tom Ridge, the former secretary of homeland security who has endorsed Bush.

"It's been elevated," Ridge added. "They've seen this erosion of America's place and prominence in the world."

Bush, campaigning Thursday with Ridge and Medal of Honor recipient Col. Leo Thorsness, argued that he's uniquely capable of tackling the challenges facing the US on a global scale.

He wants to bolster the US' relationship with Israel, which he says has suffered under President Barack Obama. He wants to recalibrate the rising regional influence of Iran and global influence of China. He wants to be the president that "destroys" the terror group ISIS, also known as the Islamic State, which has now been linked to an act of terror in the US.

"The election may revolve more around these national-security issues more now than I anticipated," Bush said in an interview here with Business Insider on Thursday.

It's a potentially awkward argument for Bush, who, by his last name alone, has faced more scrutiny because of his brother, former President George W. Bush. Even many Republicans now think George W. Bush had made a mistake by invading Iraq in 2003.