How do we explain what's going on south of the border?  We know the basics: Left vs. Right, white vs. black, rich vs. poor, Wall St. vs. Main St., social vs. traditional media.  I have spent some time in the U.S. over the years, especially in Washington, and it only takes one minute of conversation to know which side of the divide people are on – it's that obvious.  But it wasn't always that way.Recently I wrote of how it was the Republican Party that was supportive of the Civil Rights Movement and the Democrats who refused that support – that is, until John Kennedy and Lyndon Johnson made the progressive moves towards Martin Luther King. Jr. and his supporters.  Some who wrote me later noted that they hadn't known this part of American history and had just assumed that Democrat meant Left, while Republican represented the Right.  There's much we all have to learn about the democratic trajectory.  Why?  Because it could eventually become our own.Prior to the 1960s, American political parties were a mixed bag – full of traditionalists and progressives.  Consequently, finding counterparts across the Congressional aisle to collaborate with was common, and partisan interests were tame compared to what they are now.  Southern Republicans were frequently progressive and pro civil rights, while northern Democrats were frequently traditionalists.There were advantages to this.  As mentioned, common ground was possible and shared legislation frequently the norm.  Presidents could fill their cabinet posts with members of the opposite party without raising much fuss.  The post-World War Two coalition held, and America moved into its most prosperous era.But it wasn't all good, nor even fitting.  The American establishment – white, rich, male, protective of its assets, well-educated – actually enforced its hold on power because it was so strongly represented in both parties.  It didn't matter who was elected president, since the establishment always triumphed.  Or, as the famed French observer Alexis De Tocqueville noted during his touring of early America:“The surface of American society is covered with a layer of democratic paint, but from time to time one can see the old aristocratic colors breaking through.”The 1960s and 1970s were turbulent enough to shake up the political order of things.  Consequently, universities fomented rebellion against the establishment, and television and Hollywood effectively shook up the social order.  The southern Democrats suddenly found their racist policies under attack, facing a social and cultural revolution that eventually brought the Democrats into the more diversified world.  The change resulted in the Democratic Party eventually becoming the party of the centre-left.While this was happening, the Republicans, especially under Richard Nixon, began moving to the right, driven in part by the shock of the anti-Vietnam movement and its vigilance.  By the time Nixon resigned, the party was already well on its way to occupying a right-wing agenda.In other words, parties became ideologically driven and shed themselves of moderate influences.  Soon enough, the animosity between parties became so pronounced that the partisan divide became impassable.  For every Republican moderate, like John McCain, or Democratic moderate, like Joe Biden, there were hundreds more interested in political war and not in legislative compromise.It all became worse, much worse, with the cultural  revolutions of the New Millennium.  Social movements, thanks to the new technologies, suddenly had power they had never envisioned.  Women, black communities, Hispanics, anti-poverty groups, climate change advocates, and countless others suddenly mattered politically, and they successively drove the political parties even further into their ideologies, thereby making compromise even harder.Making things even more complex and difficult were the cemented divisions taking place within the populace, largely empowered by social media venues that sorted people into their ideological bubbles in a fashion that made it impossible to change minds.Think of the result.  Democrats and Republicans are more partisan.  Media has become more partisan.  Institutions and organizations have become more Left or Right.  And the public – millions of citizens – are now more politically divided than at any time in history.  This development has been both validated and enforced by the last November election in the United States.This is the America we know today.  It didn't just arrive at this place overnight, but moved in a meandering path that eventually brought it to a place with little common ground.  It has had its counterparts in Europe, Latin America, and, yes, even Canada, though none of these have proved as extreme as what is going on south of the border right now.  But it is happening everywhere.  Democracy requires a certain context to work, and its most fundamental requirement is that people desire common ground.  Take that away and all that is left is division and identity politics.  Democracy becomes hollow, just as its politics is hollowed out by the inability to find compromise and collaboration.America's present might well become democracy's future and will, therefore, not survive.  The only way it can move forward is through understanding and shared purpose, and we are increasingly on the path of tossing away those advantages.Glen Pearson was a career professional firefighter and is a former Member of Parliament from southwestern Ontario. He and his wife adopted three children from South Sudan and reside in London, Ontario. He has been the co-director of the London Food Bank for 32 years. He writes regularly for the London Free Press and also shares his views on a blog entitled “The Parallel Parliament“. Follow him on twitter @GlenPearson.