Charlie Crist's departure from the Republican Party is not just a Florida story; it's an American story – a tale of two parties driven by their ideologues, squeezing out moderate candidates, alienating independent voters and isolating the place in US politics where most things get done: the middle. Crist, a populist governor with a history of bipartisanship, bolted the Republican Party on Thursday to run for the Senate as an independent. He did so only after it became clear that he would lose his party's primary to conservative purist Marco Rubio. No matter who wins a three-way race in Florida, the factors that drove Crist from the Republicans are a microcosm of broader political and social changes contributing to polarization. “We have a deadlocked democracy,” said Pat Buchanan, a conservative commentator and three-time presidential candidate. “Both parties, held hostage by their extremes, are incapable of tackling the issues that threaten this country.” Buchanan left the Republicans for the Reform Party after he twice failed to win his party's presidential nomination. Moderate Sen. Joe Lieberman of Connecticut left the Democratic Party after losing a 2006 nomination fight to liberal Ned Lamont. He won re-election as an independent. Sen. Arlen Specter quit the Republican party last year as he faced a conservative challenge in Pennsylvania. He found a more welcoming home in the Democratic Party. And now Crist. True, they abandoned their parties for purely political reasons - to save their skins. But Lieberman, Specter and Crist had viable options outside their parties because so many voters feel disconnected from the Democratic and Republican establishments. “Unfortunately our political system is broken,” Crist said in an appeal to independent-minded voters in St. Petersburg, Florida. Democratic consultant Steve McMahon calls these voters the “invisible middle” because parties care far less about them than hard-core liberals and conservatives. This is especially the case in nonpresidential election years like 2010, which tend to draw high percentages of partisan voters. “Politicians are responding to the noisemakers of their party,” said McMahon, who helped engineer the 2004 presidential campaign of liberal Howard Dean. Dean's unsuccessful campaign brought to light one of the factors contributing to polarization: new technologies and media. He launched his bid when the war in Iraq was highly popular. That was a political problem for the anti-war candidate until like-minded people began finding and organizing each other through websites such as Meetup.org. Soon the anti-war minority became a vocal, unyielding majority. A generation ago, it would have taken much longer for people opposed to the war to realize they were hardly alone and could reshape the campaign agenda if they banded together. Fast forward a few years to the explosion of blogs and the rise of partisan cable news channels and the US is a national people who increasingly get their information from people who already agree with them. Facts become fungible. Compromise become cowardice. McMahon's firm recently conducted research that showed most young voters get political information from Comedy Central's “The Daily Show” and “The Colbert Report,” mock news shows with a liberal bent. “As a Democrat, that sounds great,” McMahon said, “but as an American, that's scary, because a lot of them think those shows are news.” Another contributor is the fact that both parties work hard – often in concert – to draw congressional districts so that most lawmakers represent areas that are heavily Republican or Democratic. This gerrymandering is designed to protect incumbents but, as technology makes the practice more precise, it also favors hyper-partisan candidates. Also fueling the trend: money. Special interest groups on both sides of the partisan divide – say, anti-tax groups on the right and abortion-rights groups on the left – raise the most money when there is a fight over their issue. So they pick fights. Incumbents who cross swords with their party's interest groups will find their fundraising drying up or even face a well-funded primary rival. Record numbers of people tell pollsters they are independents. The public's approval of both parties is at an all-time low. Will more politicians follow voters out of the major parties? Yes, said McMahon: “There is a market for independent candidates that Joe Lieberman capitalized on and Charlie Crist seized, so there will be others who explore that market.” To be sure, Republicans seem more likely than Democrats this year to impose purity tests and struggle through divisive primaries. And Democrats can point to more moderates in Congress than the Republicans could. But there is no doubt that both parties are drawing ideological lines in bright colors. Take one of the nation's most pressing issues - the debt. The two most logical ways to avoid a financial collapse like the one facing Greece is to raise taxes and/or slash entitlement programs. Conservatives won't do the former and liberals won't do the latter. And so it's a fair question to ask in the wake of Crist's decision: Is there a will or a way for compromise? In this political climate, is America willing - much less able - to make hard choices and sacrifice? “It's much bigger than Florida. It's much bigger than politics,” said McMahon, a concerned Democrat and citizen. “It's what's happening in America.”