Trump's lead is slipping but it still intrigues me as to where his support is coming from. Social conservatives prefer Cruz and to a lesser extent Carson (whose numbers are going down as well) and the establishment seems to be rallying around Rubio (now that Jeb Bush is sinking). Trump's business background may appeal to fiscal conservatives (FCs) but many FCs would be turned off by his rhetoric on other topics.
My sense at the moment is that Trump is essentially cutting across all strata and is drawing heavily from the Libertarian and Angry White Male base who feel rightly alienated from a system that under the Obama years has not served them well. In a way this makes his appeal very powerful as it draws support from groups that can shift between parties. It is the Ross Perot grouping plus more and that more, includes a substantial portion of the forty percent of Americans who don't normally vote in elections.
I prematurely predicted (like so many) that Trump's candidacy would fizzle out but it hasn't. He continues to press hot button topics that both party elites have refused to confront and has juxtaposed his position as a breath of fresh air against a system well on the way to decline. I would not wish to see him as President but his Jacksonian appeal will resonate with those who see themselves disenfranchised by a Hamiltonian consensus. This is not an insignificant number of souls and unless the establishment takes these voices seriously such undercurrents will threaten the integrity of the Union. Trump may be just one in a series of 'warnings' that are likely to follow in the future. However compounded over time they can erode, divide and bring down the center.