Previewing a possible 2016 presidential matchup, Sen. Rand PaulRandal (Rand) Howard PaulOvernight Health Care — Presented by the Association of American Medical Colleges — Key ObamaCare groups in limbo | Opioids sending thousands of kids into foster care | House passes bill allowing Medicaid to pay for opioid treatments US watchdog: 'We failed' to stem Afghan opium production Senate passes 6B defense bill MORE (Ky.), a leading Republican White House contender, blasted Hillary ClintonHillary Diane Rodham ClintonTrump mocks 'elites' at campaign rally Trump backs down in rare reversal Election Countdown: Family separation policy may haunt GOP in November | Why Republican candidates are bracing for surprises | House Dems rake in record May haul | 'Dumpster fire' ad goes viral MORE as unfit to serve as the nation’s commander in chief.

Speaking at the Iowa Republican convention on Saturday, Paul declared the 2012 attack on the U.S. mission in Benghazi the most concerning scandal of the Obama administration and laid the blame at Clinton’s feet.

Paul said Clinton’s biggest “dereliction” was to have never read the diplomatic cables from Ambassador Christopher Stevens, who was killed in the attack, providing updates for the on-the-ground situation in Libya. 

“She never read them. It’s a dereliction of duty. It’s something that should preclude Hillary Clinton from every being considered as commander in chief,” he said to loud applause. 

He said if elected president, he would have asked for Clinton’s resignation.

He said anyone who wants to be considered commander in chief must show a willingness to protect embassies and send reinforcements when necessary.

“The debacle in Benghazi started in the very beginning at the very top with Hillary Clinton deciding that the Benghazi consulate was more like Paris than it was Baghdad,” he said. “It was a war zone and it was a mistake from the very beginning to have nobody protecting that consulate.”

Paul noted that Clinton received a request six months before the attack to designate a plane on call to move personnel around Libya in case of emergency. The State Department declined the request, which Paul called “a terrible and tragic error.”

 He slammed Clinton for spending limited funds on other priorities, such as $100,000 for an electric-car charging station in Vienna, Austria, and $100,000 to send comedians to India for a “Make Chai, Not War” tour.

Paul argued the State Department shortchanged security needs in Libya to favor an array of other less essential priorities.

The State Department spent $5 million on crystal glassware, $650,000 on Facebook ads and $700,000 on landscaping at the embassy in Brussels, Belgium, Paul told delegates.