When billionaire and reality TV star Donald Trump announced his bid for the presidency last June, few pundits took it seriously.

They thought it was a stunt to boost the Trump brand, and that he would soon be gone. But Trump has not only stuck around, he is now the odds-on favourite to beat out his rivals in the race to become the Republican Party's candidate for November's general election.

Trump's simply stated goal to "Make America great again" targets the economic anxieties of voters who feel they have long been neglected by their elected officials in Washington DC.

With great success, Trump has resorted to the tried and tested populist strategy of providing frustrated and fearful voters with scapegoats. The construction of a wall on the southern border to keep out illegal immigrants - whom Trump has famously accused of "bringing drugs", "bringing crime" and being "rapists" - is a central element of his platform. So is a ban on Muslim immigration to the United States playing to a strain of terror-driven Islamophobia, which resonates with a considerable portion of the US electorate.

"It's one of the functions of a president to turn anger into hope, and I'm afraid Donald Trump is not deflecting the anger, he's intensifying it," says William Galston, a Senior Fellow in Governance Studies at the Brookings Institution in Washington DC.

Galston has written extensively on American political philosophy and public policy and admits he is one of those who did not suspect Trump's message would appeal to so many voters.

"I'm astounded at Donald Trump's success so far," Galston says.

"Many of us have been writing about the loss of trust in our governing institutions, about some of the economic problems, but I think we all underestimated the extent to which all of this was coming together into discontent, anxiety and outright anger."