Bill Clark via Getty Images Sen. Tom Cotton had a lot to say about Hillary Clinton, but not so much to offer on Donald Trump.

WASHINGTON -- Sen. Tom Cotton (R-Ark.) had a hard time coming up with a reason why he supports presumptive Republican presidential candidate Donald Trump when pressed by Chuck Todd on "Meet the Press" on Sunday morning.

Cotton, a leading proponent of an aggressive neoconservative foreign policy, was asked by Todd whether he is closer in foreign policy terms to presumptive Democratic presidential nominee Hillary Clinton than Trump, who, while promoting a bombastic and confrontational foreign policy for the United States, has also called for the country to pull back from some international conflicts and commitments. Cotton had a hard time mustering up an answer.

“Well, I can assure you that I'm not very close to Hillary Clinton,” Cotton said. “I think she's disqualified herself from commander in chief by her cavalier attitude towards our nation's secrecy laws. And she has been responsible for many of the worst decisions of the Obama administration.”

Cotton ran down a list of Clinton policies he objected to, from the reset with Russia to the NATO bombing campaign in Libya that helped topple dictator Muammar Gaddafi. He did not, however, give a reason why he supported Trump.

“What's the case for Trump?” Todd asked. “You just did a whole speech, by the way, earlier this weekend. You didn't even mention his name. You laid out a strong case against her. But you did not make a case for him. Make the case for him.”

Cotton tried to respond once again with criticisms of Clinton, before Todd cut him off to demand he give a case for Trump as nominee.

Cotton’s response was not enthusiastic: “Donald Trump can ultimately make the case for himself. But Donald Trump, like most Americans, like most Republicans, believe in protecting America's core national interests. He believes, as do I, as do most Americans, that we aren't yet doing enough to take the fight to the Islamic State. That the intervention in Libya was ill-considered and slapdash at the time."

"And we're living with the consequences of it now," Cotton continued. "That we have to get tougher when it comes to our intelligence and law enforcement practices to stop Islamic terrorism. On those matters, our party is largely united. And I say that we have the vast majority of Americans with us.”

Todd followed up by noting the freshman senator’s seeming disinterest. “You don't come across as an enthusiastic Trump supporter," Todd said. "Is that fair?”

To which Cotton deadpanned: “Maybe I don't just demonstrate enthusiasm much in life, Chuck, especially in such dangerous times as this.”

Editor’s note: Donald Trump regularly incites political violence and is a serial liar, rampant xenophobe, racist, misogynist and birther who has repeatedly pledged to ban all Muslims — 1.6 billion members of an entire religion — from entering the U.S.