The first thing is to understand what Trump isn't. He did not receive much in the way of endorsements at any point in the campaign, and in fact was shunned by the Republican party's elected representatives at both national and state capital levels. (I cannot speak of county or municipal ones.) He was spurned by the bigger donors of the party, even when he took the time to approach them. Trump at first didn't embark on a crusade to challenge the authority of these two pillars of the GOP. He offered to work with them, not against them.
So let us move on to what Trump is. Above all else, Trump is a Republican. He endorsed John McCain in 2008 and Mitt Romney in 2012. It is not hard to fit his campaign against the Democrats into the mainstream of Republican political positions of the past eight years. The 'insurgent' qualities of the Trump campaign always have been something of a media invention. Trump was expressly running against Washington, but it was a Washington in which a Republican Congress had raised annual objections to working with a Democratic White House, a Congress that sought to obstruct executive action as much as to legislate. In theory, at least, Trump could praise their efforts, could exclude them from rhetoric that portrayed government as doing nothing for the American people.
The second thing is that Trump speaks about policy options in a way that has, shall we say, a degree of frankness unusual for twenty-first century discourse, yet still leaves plenty of room for manoeuvre. He will end Obamacare, but not at the cost of people dying in the streets. Moslems need to be kept out of the country, but only temporarily. Other countries need to be held to account for their self-interested economic policies, but the treaty framework is fundamentally sound. It is a rare statement by Trump that does not include wiggle room. Examples are a reduction in the corporate tax rate to 15 per cent and that he will make the Mexicans pay for the wall (but all of it?). In this context, there is enough evidence that Trump supporters, unlike his opponents, do not take his statements at face value. In fact, they remember Trump as the author of The Art of the Deal, and regard his approach as that of a negotiator at first asking for everything.
The third thing is to understand the forces that have kept the Trump campaign afloat in spite of the hostility towards it on the part of the Republican party's paymasters and their servants in the government. The first of these is the media. Trump has received a great deal of coverage from Fox News and from MSNBC. The other force that has propelled Trump to front-runner status is his consistent success with a specific set of voters. Analysing his results by county in places like Iowa and New Hampshire showed Trump running strongly in economically depressed areas and in smaller cities lacking large universities or state government bureaucracies. He runs behind Cruz in areas that went for the ideological conservative Rick Santorum in a big way in 2012, but ahead of Cruz in areas where Santorum underperformed and Romney and Newt Gingrich ran better. Trump has picked up a significant portion of the Romney coalition (the non-elite parts) and added a lot of Gingrich's. The Super Tuesday states Trump did well in were very similar to those won by Gingrich and Romney, and not so cloe to those won by Santorum.
One Iowa county in particular caught my interest. In 1960 and 1968, Carroll county in Iowa was solidly Democratic. In 1976 it went for Jimmy Carter. But in 1980 it swung to Reagan by a pretty substantial percentage, but Reagan only squeaked out a win there in 1984, and it returned to its Democratic ways until George W Bush took it in 2000, and only Senator John McCain in 2008 lost it from the Republican column since. Could it be a marker for the old-time Reagan Democrats? One county is not enough foundation on which to base such a hypothesis, but it is a fact that Trump had a narrow lead over Ted Cruz there, whereas Marco Rubio finished firmly in third place, his elite-sponsorship doing him no good at all. There may be signs that supporters of Cruz are swinging to Trump, as recent polls in Florida show Trump gaining as Cruz' percentage falls. The bedrock of Trump's support rests on what one might call 'rank-and-file' GOPers. The message from the party Establishment has so far fallen on deaf ears.
The other factor here is turnout. Turnout for GOP caucuses and primaries has been way up this year compared to 2008 and 2012. Some of these people are coming out to vote for Trump, and it appears some are coming out to vote against him. So far it is not so clear how many of the new Republicans are voting for Trump. Initially, at least, late deciders voted against him. In national polls his 'negative value' among Republicans has been fairly stable throughout.
The dilemma confronting the GOP leadership hasn't really sunk in, by all appearances. They are acting as if they believe they will lose down the ticket if Trump is at the top of it. They are trusting that if they block Trump's bid for the nomination by any means possible, their supporters will still turn out to keep Hillary Clinton out of the White House. But what if they don't? What if they are so angered by the shenanigans of a party leadership turning on the voters' choice that they stay home? I did a calculation that suggested, using evidence from Quinnipac University polls, that Trump might cost the Republicans about 15 per cent of their base vote, but it is impossible on the basis of that data to calculate how many of Trump's supporters are voting Trump or nothing.
American political parties are built on a 'strategic triad' of elected politicians, donors and voters. Each has a vital role to play in the electoral process. It has been a long time since we have seen the kind of civil war now going on among Republicans in an American party, and the reality is that these outcomes never end well for the victims. The Democratic party ran against both George McGovern in 1972 and, to a lesser extent, Jimmy Carter in 1976 and again in 1980. The result was twelve years of Republican control of the White House, and it could have been longer had it not been for Ross Perot's quixotic tilt in 1992. Unless this civil war is rapidly brought to an end, or some unforeseen event occurs between now and November, it looks like the Republicans will basically be a Congressional and state-house party for some time to come.