I'm just going to let everyone know that this post is not going to be relevant in about 2 months when everyone decides that Donald Trump is not a viable candidate for the Republican primary. Now that we got that out of the way, let's actually do something worthwhile when we talk about Trump. We could, in theory, have an in-depth conversation about Euchre or we could talk about the lack of a policy/issues link on his website. Yet, not a single media outlet is reporting on the fact that Donald Trump cannot even manage to put his policies on his website for his presidential run. What is more interesting is what would be the ultimate ceiling of Trump.
Latest polls are showing that Republican voters are pretty evenly split on Trump. Public Policy Polling (PPP) found that among Republicans, Trump had a favorability of 38/43 (-5 net favorability). Monmouth found a very similar result showing that Trump had a favorability of 40/41 (-1 net favorability). While this is an improvement for Trump in the Monmout poll in June of 2015, showing him at a 20/55 split (-35 net favorability), it means that the majority of voters have already formed an opinion of him. It is easier to form a positive impression on voters if they are unaware of you but once you have a high enough name recognition, people's opinions are largely unchanged. Of course, Trump with his rambling speeches, uninformed and racist comments may be a more volatile candidate than other politicians.
Based on name recognition, the candidates that compare to him are Jeb Bush (50/30 per Monmouth) and Mike Huckabee (53/23). Marco Rubio is fairly close, as well (53/19). Their net favorability is much much higher than Trump's. In case you think I'm cherry-picking by using Monmouth, I will concede that Jeb's net favorability with PPP's poll is -3 which is much closer to Trump's; however, I am not sure that it is the most accurate representation of his numbers.. There's not another candidate in this field with such high name recognition and as much negativity as Donald Trump unless you happen to believe that PPP's numbers for favorability are much closer to the truth than Monmouth's, Quinnipiac (showing 52/20 in May), or any major poll that I can find. So what do we do with that?
We can compare it to the previous presidential primary seasons, only there is not a candidate with such a high name recognition and near even net favorability from 2011 (using the same timeframe).
Currently, Trump is getting around 15% in the national polls. This is about where he's at in state by state polls, as well. His most favorable numbers are coming from Ted Cruz supporters and those who describe themselves as very conservative. In PPP's poll of Michigan, Trump has a favorability rating of 41/44 (post Trump announcment bump) among Republicans which would be in line with what is found nationally. With that favorability rating in mind, he had a +15 net favorability among those who self-identify as very conservative. With those numbers in mind, he is getting 14% in the polls for the primary in a very crowded field, that's good enough to tie for second place.
Trump's biggest strength right now is that there are 16 declared candidates vying for the nomination. All of these candidates are stealing votes away from each other and allowing there to be no frontrunner candidate. As the field shrinks, the candidates will be trying to get voters who supported their opponents earlier on. This is where Trump fails. Only 6% of Michigan Republicans see Trump as their second choice for the presidential nomination. Jeb and Scott Walker are in double digits as the second choice and Rubio is the second choice of 9% Michigan Republicans. Tables for how Trump fares in other states as the second choice will be forthcoming.
Trump's ultimate ceiling as a first-time candidate will depend on how quickly the field is narrowed. As of current writing, his ceiling is probably about 10-15% in each primary with a little higher numbers in southern states. Trump is running at the heart of the TEA Party base. Unfortunately, I see no evidence that the TEA Party is any more than 15% of the Republican electorate nationally (I actually think it's closer to 10%). If you assume that the TEA Party was represented in the 2012 Republican primary by Newt Gingrich, Michele Bachmann, and Herman Cain, the popular vote totals for the primary give them just under 15%. In a large field, he may be able to grab some delegates but ultimately, the most likely outcome of Trump's campaign is Herman Cain.