[Warning - this is a bit on the rambling side and may be further edited as time permits]
The typical American liberal or progressive should be horrified by the prospect of Donald Trump presidency. If he runs the country the way he has run his companies we'll be bankrupt within months. He will turn the country into a laughing stock and we will be less-safe domestically and internationally than we are now. He will enable a wave of xenophobic, racist, and isolationist sentiments and actions that have remained been largely outside the political mainstream since the heyday of George Wallace's presidential campaigns. If elected, he will run roughshod over our system of governance, and likely create a constitutional crisis that will make Watergate look like quaint by comparison. More frightening perhaps is that his supporters will be either disappointed by his predictable failure to deliver on his outlandish promises (like forcing Mexico to pay for a complete wall at the border or slapping China with prohibitive tariffs, or returning manufacturing jobs to the United States) and lose all faith in democratic processes, or be emboldened to take matters into their own hands and exact "justice" on those they perceive to be thwarting Trump's agenda.
This is all to the bad, of course, but it sits on a sandy foundation. Simply put, Donald Trump will never win the general election. The nightmare scenario is just that, a nasty dream, not a vision of the future. If he wins the Republican nomination (a distinct possibility from where we sit today - although it will be close) it will break that party into pieces. It would require a badly fractured, multi-ballot convention that would play out in the media in real time exposing all of the ugly fractures within the party. The party establishment, already nauseated by his theatrics and bruised from losing will either refuse to support him, or coalesce around a third-party run by a runner up, perhaps a Rubio/Kasich ticket, or Bush/Christie pairing. There is a precedent for this, albeit not a pleasant one, in the actions of the Dixiecrat/white supremacist/segregationist faction within Democratic party in 1948.
Unwilling to support the party nominee (Harry Truman running on a platform that contained some mildly civil rights-oriented planks), they split from the party, set up a convention, and nominated South Carolina Governor Strom Thurmond for President, with Mississippi Governor Fielding Wright as his running mate. They appeared on the ballot in thirteen southern states. Remarkably, they won the electoral college in four states (LA, MS, AL, and SC). What is important for our story here is that once the election was over, the dissidents returned to the Democratic party without fanfare and without punishment, as they had run no local or state candidates, only the top of the ticket.
Should Trump win the nomination, he will quickly face a challenge from the Republican Chamber of Commerce/Wall Street establishment, who would rather see a President Hillary Clinton(or President Bernie Sanders) than President Donald Trump. The establishment would work first and foremost to shore up their control of the Senate. The pledges made by all of Republican candidates to support the eventual nominee are about as binding as Velcro: easily pulled off the moment one needs to do so. The Republican national committee will bend over backwards to help this - setting aside rules and protocols so that whatever form the third party takes it will get on the ballot in most states - including simply taking over the ballot spots of the many perennial third-parties that get on the ballot on states across the country. Most will happily be bought off.
But back to my point - the progressive case for Donald Trump. I am of the opinion that Hillary Clinton is poison to the progressive wing of the Democratic Party. On nearly every single issue she stands in opposition to progressive ideals. She was wrong on the Iraq War(s), wrong on Guantanamo, wrong on NSA wire-tapping, wrong on bank bail-outs, wrong on (so-called) free trade, and wrong on "too big to fail". She was a guiding light in the now defunct Democratic Leadership Council that sold the party out to Wall Street, and appears incapable of sticking to any principle save self-preservation. She will continue to be dogged by ethics concerns, and the e-mail server issue will rear its ugly head throughout the next twelve months (even though it is spurious as a legal and ethical issue - it does call into question her judgement). In the end, Clinton is unlikely to win the presidency - she does not create the kind of excitement that President Obama did as a candidate, the critical African-American and Latino/a voters who propelled his elections will not turn out in the same numbers to support Clinton. There is no evidence that she has generated that level of enthusiasm. Above and beyond that, as some have said, the presidency is not something to passed back-and-forth between a few families. If she is elected, every election since 1980 will revolve around someone in the immediate Bush/Clinton political family tree. That isn't democracy, but aristocracy (at its worst, and banana republic chicanery at best).
I argue that progressive and liberals should want to see Trump win the Republican nomination. I make this argument because this would present the strongest possible scenario for Senator Bernie Sanders to win the nomination of the Democratic Party and to win the general election. At its simplest, in a scenario where the Republican and conservative vote is divided between two candidates, Candidate Sanders would then stand to pick-up the few critical swing states to the Democratic column - think Ohio, Virginia, Colorado, and the all-important Colorado. It would improve Democratic changes in West Virginia, Tennessee, North Carolina, and Indiana as well, currently assumed to be lost to the party for a generation. It would assure that Pennsylvania stays in the (D) column. The enthusiasm for a Sanders candidacy would bring voters to the pools in states where the Republican senatorial candidates or incumbents are weak or out-of-step with the general political tenor of their states.
Okay, what are some of the (remote) dangers if this scenario does not play out well?
No candidate wins a majority of the Electoral College. This outcome throws the election into Congress, with the House selecting the president and the Senate the vice-president. Simply put, this would absolutely assure that Trump would not be elected president. House and Senate Republicans would support the establishment candidate, and given their control over both houses would do so quickly. 30 state delegations in the House are majority Republican - and only the votes of 26 states are necessary to select the president. In the Senate, votes are by individual, with a Republican majority, the Establishment (third-party) Republican would win. In an ideal scenario, especially in the House, enough tea party/freedom caucus Republicans would threaten to support Trump (since the House may select from the top three candidates) that Establishment Republicans would be forced to make a deal with Democrats for their votes- opening up all sorts of possibilities for extracting concessions. However, this scenario is highly implausible - in part because it has happened only twice in our history, and in the period before strong party affiliation emerged.
The anti-establishment, and xenophobic sentiments that Trump has tapped prove uncontrollable, and the election campaign is marred by ever-more outlandish rhetoric and episodes of violence. Frankly, I see this as extremely unlikely. The vast majority of Trump's supporters are not bad people, but rather the very sorts of working-class white and rural Americans that the last 35 years of economic change have effectively abandoned to their fates. They have been duped by Establishment Republicans since 1980s, used as voting fodder spurred by cultural issues and then shunted aside the day after the election and given nothing in return except economic policies that have devastated their livelihoods. They believe that the Democratic Party has decided to ignore them in favor of an electoral strategy that relies on urban voters on the two coasts and in the major interior cities and suburbs. When was the last time a Democratic president did anything for Appalachia? Maybe Lyndon Johnson. They believe that they and their children bear the brunt of the nation's wars because the children of the middle class do not serve. The failures at the Veteran's Administration were a political football for the middle-class and the elites in both parties, something to be consumed while reading the Wall Street Journal or listening to NPR, but for Trump's supporters represented a fundamental betrayal and insult to their sacrifices. What I am trying to get at here is that it is unlikely that his supporters will turn to violence. They see themselves as law-abiding in a system that has become law-less. That commitment is central to their understanding of the world - duty, sacrifice, and loyalty. Most are simply frustrated (and rightly so - which is why they ought to see common cause with the Black Lives Matter movement) by a political and economic system that either ignores them or treats them like rubes.
Donald Trump wins. We must admit to this possibility, but it is less dire than it sounds. For all of his bluster on certain issues he appears to glide a relatively moderate social and economic stance. Some may recall the election of Jessie Ventura to the governorship of Minnesota. He won the election on the basis of his personality and a studied disregard for the advice and predictions of the punditry, and the establishment of both parties. However, once in office he was singularly unable to accomplish anything significant. The Democrats and Republicans in the Minnesota legislature, and in the state's congressional delegation refused to work with him. A Trump president would be a lonely president, thwarted at every turn by the lack of a support base on Congress.
