【明報專訊】OVER the past three months the United States has seen two cases of alleged police brutality resulting from discrimination against black Americans, leaving one dead and another injured. The incidents have added to the explosiveness that attends the upcoming presidential election to be held later this year amid the COVID-19 pandemic. For months, a wave of mass protests against racial discrimination and police brutality has swept across nearly all US large cities and small towns east and west. The latest case of police brutality this month has even galvanised black NBA players into boycotting matches at one point. At the same time, vandalism and theft during the protests in some cities have provoked street patrols by armed white vigilantes, and even a shooting incident in which a white teenager killed two. All this has resulted in a societal rift that risks driving the country to the verge of a civil war. The two major political parties of the US are both at their wits' end about this storm. Whether the protracted chaos and unrest will give an advantage to US President Trump who brandishes the flag of "law and order" or even help him catch up from behind and win re-election has become the concern of observers.