What is the cause of Trump's popularity?

To begin with, his strong defense of Israel is in line with past pre-election statements of major candidates and is a hygiene factor. His references to mistakes in Iraq, Egypt, Libya and Syria bring under one umbrella the Republican George W. Bush and Democrat Obama eras, even though he only names the latter. These references are also in sync with recent polls that suggest growing voter apathy toward the US' global wars.

Further, the American voter has been buffeted by the double whammy of the global financial crisis that refuses to go away and automation-driven technology that now threatens to take away even more jobs. The essential part of Trump's speeches is, the US is being taken advantage of by both its security and economic partners. This is music to voters' ears. So are his denunciations of North American Free Trade Agreement ("complete disaster") and Trans-Pacific Partnership ("rape of our country").

Which segment does Trump's focus on Islamic radicalism and Mexican "criminals" appeal to? This is more complex. As one writer put it colorfully, US society can be visualized as divided into erstwhile feudal landowners, white slave-drivers and slaves. It is the figurative déclassé white slave-drivers who are rebelling against the Democrats and who find the anti-Muslim and anti-Mexican focus gratifying. That this segment has been shaken by a black president adds piquancy to their protest.

Will Trump's popularity extend to the wider electorate? This will of course depend on many factors. It is possible that Trump may finally trip on some egregiously inadvisable remark such his recent rhetorical attack on Khizr and Ghazala Khan, parents of an Army captain who was killed by a suicide bomber in Baghdad in 2004. There are some 3.3 million Muslims in the US, many of whom have been offended by him.

Trump needs to extend his vote-bank to Mexicans and women as well. The US establishment's isolationist perception of Trump's views on foreign policy could eventually cause serious problems for him.

What is clear, though, is that Democrat Hillary Clinton will need all her strengths and his foibles to beat the feisty Trump in the forthcoming presidential elections.

The author is a former Lecturer in Marketing at Cranfield University.