‘Ted Cruz was one of the sharpest, brightest students I’ve ever taught at Harvard.’

I’ve never forgotten that glowing tribute to the Republican presidential candidate – who won a big victory in the Wisconsin Primary last night - from one of America’s most famous and eminent lawyers, Alan Dershowitz.

Mainly because Dershowitz is a diehard liberal, so would instinctively disagree with almost every word that comes out of Cruz’s mouth.

But also because he taught over 10,000 students at Harvard Law, most of them exceptionally clever minds or they wouldn’t be at Harvard to start with.

So Cruz must be a highly intelligent human being.

Harvard professor Alan Dershowitz remembered former law student Ted Cruz as one of the brightest minds he's ever taught - and he's taught thousands. Cruz, seen Wednesday in the Bronx, is also the embodiment of the hard-line Conservative right in America

Dershowitz, speaking to me on my old CNN show, added: ‘Ted Cruz deeply believes in what he’s doing, he’s deeply principled, he thinks he’s doing the right thing. That doesn’t mean it is the right thing, and he’s very hard to get off that principled argument. He was not a compromiser, not somebody who tried to make friends by accepting what was then the political correctness of the day.’

So far, so good you might think?

Nothing wrong with a very smart man who has firm principles and believes in what he’s doing.

Particularly when Donald Trump, his main opponent for the Republican nomination, is seen by many critics to be a deeply UN-principled, shameless opportunist.

The only problem is that Ted Cruz’s principles, as Bette Midler tweeted today, are ‘somewhat right of Attila the Hun.’

Attila, a fearsome power-crazed barbarian ruler of the Hunnic Empire in the 5th Century, had pretty strong principles too. Notably: ‘Trample the weak, hurdle the dead.’

A perfect metaphor, perhaps, for a ruthless career politician like Cruz who is equally loathed by colleagues on both sides of the Senate for his abrasive ‘outsider’ onslaughts against pretty much everything federal government stands for.

Most of the attention in this GOP nominee race has centered on TV and media superstar Trump.

But flying methodically under the radar has been a candidate who is inherently far more right wing than Trump.

Ted Cruz shares many of Trump’s character traits – including a massive narcissistic ego, a penchant for crowd-pleasing populist rhetoric and an aggressive, attack-dog style against opponents.

Where they differ, crucially, is that Cruz is deadly serious and very deliberate about every word he says, and has spent years plotting and scheming to radically change America forever.

Cruz is not just pandering. He's a brutally ideological zealot. He’s opposed to same-sex marriage or civil union, he voted against the Violence Against Women Act, he’s anti abortion including rape and incest. He claims that more guns mean less crime, despite evidence to the contrary and he denies the existence of man-made climate change

His astonishing, and scary, ambition manifested itself publicly in 2013 when he threw one of the great tantrums in U.S. political history over Obamacare and successfully managed to shut down the government for 16 days. A self-aggrandising stunt which temporarily put 800,000 Americans out of work and cost the U.S. economy $22 billion.

Further, he actually stated that elected officials who didn’t vote to defund the Affordable Care Act were akin to Nazi appeasers.

Really? Anyone who supported a health care proposal which gave 30 million impoverished and uninsured Americans health cover was as morally culpable as people who tacitly enabled the mass murder of 11 million people including millions of Jews exterminated in gas chambers?

Cruz is not, as many believe Trump to be, just pandering to the hard-line Conservative right in America, he IS the hard-line Conservative right in America; a brutally ideological zealot who wants to drag his country kicking and screaming back to the very dark days of bigoted fear and hatred of government.

Consider some of his basic, very entrenched beliefs:

He’s opposed to any kind of same-sex marriage or civil union, believing marriage should be between ‘one man and one woman’. Such is his utter intolerance of all things homosexual, he even attacked the mayor of Dallas for marching in a gay pride parade.

He resolutely supports the death penalty.

He voted against the Violence Against Women Act.

He’s anti all abortion, including for pregnancies caused by rape and incest.

He wants to slash funding to Planned Parenthood.

He repeatedly claims that more guns mean less crime, despite all statistical evidence to the contrary. In fact, he's so gun-mad, even by Republican standards, that he makes breakfast for his family by wrapping pieces of bacon around a machine gun.

He denies the very existence of man-made climate change.

He’s so driven by his Christian religious beliefs that he opposes any notion of separating Church and State. ‘Any president,’ he said, ‘who doesn’t begin every day on his knees isn’t fit to be Commander-in-Chief.’

He claims Christians can’t be terrorists and have committed no such acts of terror for hundreds of years.

He wants police to ‘patrol and secure Muslim neighbourhoods inside America’ – an act described as ‘terrifying’ by U.S. Muslims.

Trump has been regularly described as the most dangerous man in America.

Trump has been described as the most dangerous man in America - but he's a businessman at heart and he's trying to get the deal done - in this case get elected

But Trump, at his heart, is a businessman.

He’s spent his life doing deals, often taking extreme starting positions – whether he’s buying buildings or golf courses, or haggling over a TV show salary - to secure leverage and then negotiating back to a more reasonable place.

He’s been adopting the exact same strategy in this presidential race – to great effect.

The presidency is just another deal to Trump, albeit the biggest of his life.

To win the White House, he has to first win the Republican nomination, and he’s calculated that the best way to do that is to hammer away with tough-sounding messages on hot button Conservative issues like Islamic terrorism, immigration and abortion.

It’s undeniably made him sound at times both racist and sexist, neither of which I have ever heard him be in the ten years we’ve been friends.

But I suspect everything he’s been saying is negotiable, from his Mexican wall to short term Muslim ban.

Trump has sounded racist and sexist this campaign - no doubt about it - but he's never been remotely either of those things in the decade we've been friends

Whether you love or loathe Trump, ask yourself which is the more dangerous potential leader for America right now: a ‘deeply principled’ right wing evangelist lunatic who means exactly what he says, or a pragmatic extrovert businessman with a big mouth whose whole career has been built on compromise?

Of course, there may be other candidates who throw their hats in the ring if the Republican nominee battle is still undecided by the time of the party’s Convention.

For now though, it’s likely to be Cruz or Trump.

I personally wouldn’t vote for either of them, even if I were able to, because of their refusal to even countenance new gun control laws.

But I can say this with some certainty:

Trump wouldn’t be nearly as dangerous as people fear.