from Bring Back Political Parties by Kevin Williamson at National Review :
The Democratic party had an excellent reason to exclude Senator Bernie Sanders, the same reason the Republican party had to exclude Donald Trump: He wasn’t a member of the party. Sanders is a socialist independent who briefly joined the Democratic party for reasons of pure political utility. Donald Trump is a . . . whatever in tarnation he is . . . who joined the Republican party for the same reason. Trump, a sometime Democrat and Hillary Clinton donor who had been aligned with the politically insignificant Reform party, knew that he needed the GOP’s machinery to win the presidency, or to even get close, and Sanders knew that his influence and power would grow from running in the Democratic primary rather than as a U.S. affiliate of the Monster Raving Loony party. (I miss Screaming Lord Sutch.) Sanders is no fool: His lakeside dachas aren’t going to pay for themselves, and there’s no money in third-party presidential campaigns — that’s just an expensive hobby. Ask David Koch.
There is a contradiction within American progressivism, which seeks to make the political process more democratic while pushing the policymaking process in a less democratic direction. For a century, progressives have championed more open primary elections and open primaries, popular ballot measures, referendum and recall processes, and wider voter participation. At the same time, progressives, particularly those of a Wilsonian bent, have sought to remove the substance of policymaking from democratically accountable elected representatives and entrust it to unelected, unaccountable bureaucracies in the belief that panels of experts immune from ordinary democratic oversight could make hard decisions based on reason and evidence rather than on short-term political necessity and popular passions. They regarded the political parties and their infamous smoke-filled rooms as embodiments of corruption and old-fashioned wheeler-dealer politics at odds with the brave new centrally planned world they imagined themselves to be building.