Is 'Dangerous' Donald's Campaign Unstoppable?

Republicans voting in 11 Super Tuesday states are in absolutely no doubt about who the front runner is.

Donald Trump is so far ahead in most of the polls he appears unstoppable.

Here in Alabama he drew record crowds to a rally in Madison.

His speech was unchanged from the familiar themes; making America great again, bringing jobs back from China, building a wall on the Mexican border.

But the crowd was rapt, listening closely, nodding.

They told me they had a lingering sense that they had been left out, and that finally, here was someone who gave them a voice in the national conversation.

Remarkably, Trump's done it by spending very little compared to his rivals on advertising and field organisation.

His is a campaign of showmanship and social media.

It's upended the nomination race and challenged almost all of the Republican party's conventional wisdom.

His nearest rivals are scrambling to keep up.

Texas Senator Ted Cruz must win his adopted home state or face disaster.

And establishment favourite Marco Rubio needs to keep up until his home state of Florida votes later this month.

He has accused Trump of being racist after he refused to disavow the Ku Klux Klan, but hasn't done any real damage so far.

And while rivals are trying to find a way of denting "The Donald", Trump's broad appeal is morphing in to something more powerful, more permanent.

Now he is starting to bring in big endorsements; New Jersey governor Chris Christie, and the hugely popular Alabama senator Jeff Sessions.

A political editor at a US news network described the Christie move as representative of the Republican party's final stage of grief - acceptance.

Most of the party elders are desperate to do something to stop Trump, but they appear to still be reeling from the businessman's hostile takeover.

Now a twice-divorced New York billionaire has been forgiven his sins by some of America's most conservative voters, and those who view him as a morally untethered danger to the establishment are running out of time to stop him.