A Trump supporter (R) yells at a demonstrator (L) after Republican U.S. presidential candidate Donald Trump cancelled his rally at the University of Illinois at Chicago March 11, 2016.[Photo/Agencies]

The violent clashes in Chicago on Friday, between supporters of Republican presidential candidate Donald Trump and protestors opposed to his positions on various issues, have reinforced the "smell of gunpowder" his divisive comments have produced in the presidential election campaign in the United States.

The provocative racist rhetoric Trump has used in his campaign, such as his calling Americans of Mexican descendant "rapists", his proposal to erect a wall along the US-Mexican border and his opposition to allowing Muslims to enter the US, seem to be challenging the "political correctness" of US politicians.

It was no doubt beyond the expectations of the Republican Party that Trump would gain a leading position over the other Republican nominees. But approving Trump as the Republican candidate for president would violate traditional Republican values, while nominating another candidate would likely cause Trump to split the Republican vote as an independent candidate, and thus would make the Republican Party more likely to lose the presidential election.

The Trump phenomenon has been created by the growing financial pressures felt by many in the middle class in the US since the onset of the global financial crisis, and thus the need for an outlet to vent their accumulated grievances and angers over globalization and numerous domestic issues.

Trump's populist style has satisfied their needs.

However, the rise of a racist presidential candidate in the US political arena has generated a sense of unease across the rest of the world. Trump's emergence has added uncertainty and unpredictability to US politics that is usually predictable. Some people have even compared Trump to Benito Mussolini and Adolf Hitler.

The negative influence Trump's campaign has had in the US and beyond is enough to testify to the existence of some latent problems in the US election system.