The real-estate mogul could wind up winning the Republican nomination and even the race for the White House, but he will first need to overcome highly negative favorability ratings among both Republicans and the general public. An even bigger issue highlighted by Trump’s rise, notes Paul Saunders, is the growing divisions within the GOP.

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Donald Trump’s victories in the New Hampshire and South Carolina primaries have led many to ask whether the businessman-turned-television personality could eventually win the GOP nomination or even the November 2016 presidential election. The short answer is that it is indeed possible, though he would face significant challenges in securing the nomination and especially a general election victory. No less important, however, are the profound challenges facing the Republican Party.

Expert assessments of Trump’s prospects have improved dramatically since the spring and summer of 2015, when most observers did not think that Trump’s support in polls would translate into votes or that his sometimes offensive statements would force him out of the race. By September, a Republican Party political strategist had produced a confidential memorandum [ https://www.washingtonpost.com/apps/g/page/politics/memo-on-donald-trump-from-ward-baker-to-nrsc-senior-staff/1898/?tid=a_inl ] to party leaders outlining how the party and congressional and state candidates could manage the consequences of Trump’s nomination.

In December, party leaders privately acknowledged another possibility: a contested party convention, resulting from the failure of any one candidate to win sufficient delegates in state-by-state races. [ https://www.washingtonpost.com/politics/gop-preparing-for-contested-convention/2015/12/10/d72574bc-9f73-11e5-8728-1af6af208198_story.html ] Trump’s performance so far makes each of these outcomes increasingly realistic.

Roadblocks to the Nomination

The forces in Trump’s favor are anti-establishment voter anger and a sense that Trump is an “authentic” outsider, a divided Republican party producing multiple weak candidates who struggle to match Trump’s popularity, and momentum going into early March, when twenty-one states will award Republican delegates during a two-week period. Polls suggest that Trump could continue to do well in many of these states.

In the best-case scenario for Donald Trump’s campaign, continuing primary victories would strongly encourage Republican elites and voters to consolidate around his candidacy to win tactical advantage against the eventual Democratic nominee by uniting sooner and reorienting the GOP’s focus outward rather than inward. In another favorable scenario for Trump, continuing battles among multiple second-tier candidates, now limited to Senator Ted Cruz, Senator Marco Rubio, former Governor John Kasich, and retired neurosurgeon Ben Carson, would allow him slowly to build the majority of delegates needed to win the nomination.

“High negatives”—a large number of potential voters who don’t like Trump, even among Republicans—are perhaps the largest obstacle facing the Trump campaign. Indeed, after reviewing exist polls, the respected political statistician Nate Silver set Trump’s net favorability rating at -25% among Republicans. [ http://fivethirtyeight.com/features/donald-trump-is-really-unpopular-with-general-election-voters/ ] While 33% of Republicans evaluate Trump favorably, some 58% see him unfavorably. Trump’s net favorability among independents and Democrats is even lower, at -27% and -70%, respectively. This enduring opposition to Trump could prevent him from winning sufficient delegates prior to the Republican Convention, to take place in Cleveland, Ohio in July 2016.

Trump’s approach to financing and running his presidential campaign may well become another obstacle. Trump has famously stated that he is financing his own campaign rather than courting major political donors. In practice, Trump appears to have relied heavily on loans to his campaign (which the campaign would presumably repay in the future), small donors, and complicated arrangements through which some of his existing employees work for his campaign while being paid by his companies. At the same time, some reports suggest that about one-fourth of his campaign expenses are actually payments to his own companies. [ https://www.washingtonpost.com/opinions/five-myths-donald-trump-tells-about-donald-trump/2016/01/28/b7cead16-c46e-11e5-9693-933a4d31bcc8_story.html ]

In 2015, Trump appeared to resist creating an expensive full-scale traditional campaign organization focused on identifying and mobilizing his supporters; if he is to be the nominee and eventually to win, he is likely to need such an organization. At a minimum, he will suffer for not having it. Indeed, from this perspective, Trump’s second-place finish in the Iowa Caucus—which usually requires a strong “ground game,” as political operatives put it—is all the more impressive.

Damaging for the GOP

Ultimately, however, whether or not Donald Trump wins the Republican nomination, the 2016 election cycle could be a very damaging one for the Republican Party. If Trump wins the nomination, many establishment Republicans—including elites and ordinary voters—may refuse to back him. Conversely, if Trump wins the largest share of delegates (perhaps 35% to 45%) but fails to win an outright majority and loses the nomination in a so-called brokered convention, his supporters may turn on the GOP. In that case, Trump himself may choose to run as an independent candidate.

This problem—divisions in the Republican Party—may ultimately be the most significant roadblock for a Trump presidential campaign. That said, US presidential elections are choices between alternatives, not up-or-down votes. Barring serious legal problems stemming from the investigation of her personal email server, Hillary Clinton is quite likely to become the Democratic nominee and is herself a polarizing figure, both among general election voters and among Democrats, something powerfully demonstrated by Senator Bernie Sanders’ early successes.

If Donald Trump does win the Republican nomination, the 2016 election could be decided less by who has the most supporters than by who has the most opponents—and whether they decide to vote or stay home.