Texas Republican Sen. Ted Cruz promised Monday to return to a government by the Constitution and "stand for liberty" as he officially announced his 2016 presidential bid.

As the first major presidential candidate to officially declare, Cruz told the crowd of students at Liberty University in Lynchburg, Va., what he sees for the future of the country.

(Watch Cruz's full speech and read the transcript, here)

But how does constitutional expert and Fox News senior judicial analyst Judge Andrew Napolitano feel about Cruz's adherence to the Constitution?

Stuart Varney sat down with Napolitano to ask that question this morning.

The judge said he likes Cruz's views toward the Constitution overall, except when it comes to the senator's views on using U.S. military force overseas.

"I think Ted Cruz would probably join all the other Republicans but Rand Paul with the idea that we should - to use Woodrow Wilson's phrase - make the world safe for democracy, which means perpetual death and perpetual war," said Napolitano, arguing that Paul would be the only candidate who shares his views on only fighting "defensive" wars where the nation is truly under an imminent threat.

Varney countered by asking which war of the last 100 years Judge Napolitano would have supported.

Other than World War II, Napolitano said he would not have fought any of them.

"The purpose of war is to be the absolute last resort to save the nation. It is not to be used, in my view and the Constitution, to move national borders because we don't like what's going on in other countries."

Napolitano also said his "heart sank" when he heard Cruz talk about a "federal right to education."

Watch his full analysis above.