Nationalism, populism and leaders with blond hair. Those are just some of the factors that have been cited to compare the rises of Donald Trump and the Brexit movement. And it's fair to say there are similar forces driving both phenomena. But there are stark differences too.
How they're similar
The movements on both sides of the Atlantic are animated by voters' dissatisfaction with the political elite. Nigel Farage, who sparked the recent growth of the UK's anti-European Union movement, and Boris Johnson, who is its highest-profile face, are atypical politicians. Neither is the rebel that Donald Trump is, but all three men share a straight-talking nature and celebrity status, relative to most politicians. They tend to "tell it like it is," and many voters applaud them for it. At times they rely more on persona and organic media interest than on rational arguments.
A second similarity is where their support comes from. Both the U.S. and UK have seen economic growth return following the financial crisis, but in a muted fashion that's almost nonexistent for many middle- and low-income workers. People have begun to look for alternatives. Donald Trump is that alternative in the United States, and Brexit is the option in the UK.
Furthermore, supporters of a Brexit tend to be older, much like Trump supporters. Younger British voters tend to favor a remain vote in the UK, while younger Americans are more opposed to Trump.
Brexit tends to resonate more with small business owners and the self-employed, and Trump tends to with similar voters in the United States. Meanwhile, big businesses have for the most part tried to highlight the economic risks of a Brexit. JPMorgan Chase CEO Jamie Dimon highlighted the risks a Brexit poses to jobs, and exit camp immediately tried to spin that to say that big banks were bankrolling the anti-Brexit campaign. A similar, anti-big bank rhetoric has come from Trump, who has attacked Hillary Clinton for her links to Wall Street.
And then there's immigration. Concern about excess immigration is certainly a topic where both groups share ground, whether it's slowing the flow of Mexicans into California and Texas, or preventing Middle Eastern refugees from entering Britain at the same rate they've entered Germany.
This similarity should not be overplayed, however. The main immigration debate in the UK focuses chiefly on people legally allowed into Britain — EU Passport holders — rather than refugees or illegal immigrants. The refugee crisis in Europe has added spice and column inches to the debate, but since the UK is outside of EU's free border zone (an often overlooked aspect of its special EU status, alongside being outside of the euro currency) refugees cannot move freely into the UK once they are within the EU anyway. Thus, many Brexiteers oppose the severity of Trump's rhetoric on that topic.
How they're different
Geoff Caddkick | AFP | Getty Images
Passer-by views a mural showing Donald Trump (L) kissing the former Mayor of London and Conservative MP, Boris Johnson, in Bristol, England on May 24, 2016.
And that difference in tone isn't the only place where very real differences exist between Trumpism and support for a Brexit. Another is free trade. Trump opposes free trade and advocates protectionist measures. It's often incorrectly reported that the Brexiteers stand for the same thing. However, they seek free trade just as much as the UK's remain camp does — they just seek it in a different way. The Brexit debate is more about whether the exit camp's articulated path to free trade outside of the EU is realistic. Their intentions are less in doubt — they want free trade with Europe and with countries outside it.
Second, dissatisfaction with the elite in Trump supporters' minds is based around the political elite in Washington. For Brexiteers, it's about bureaucrats in Brussels. There is a crucial difference here: Trumpism is an argument against elected officials at home, Brexit is an argument against unelected officials abroad. The sovereignty of the United States is not in doubt whether under Clinton or Trump — it's a battle of which American, or group of Americans, yield power. The Brexit debate is different: It's about a loss of sovereignty from the UK to foreign shores, where leaders are often not even elected.
Third, the rise of Trump is a relatively recent phenomenon. Yes, one can argue that there are origins of it in the rise of the Tea Party, but either way, the sentiments behind it have developed in the last decade. Clearly the rise of The Donald himself is very recent indeed — less than a year ago, his possible candidacy was laughed at in Washington circles. In contrast, anti-EU sentiment in the UK has existed for as long as the European Coal and Steel Community (the first installment of what is today the EU) was founded in 1951. Since then, Europe is an issue that has divided the Conservative party, and was responsible for the fall of the Thatcher government and many of the problems of the Major government. It's also often divided the Labour party too. There was even an exit/remain referendum in the UK on Europe before, in 1975, which was in fact delivered under a Labour government, highlighting the extent and longevity of the anti-Europe debate in the UK.
The differences between Trump supporters and the Brexiteers are so fundamental that they discount any implied conclusions from the similarities. In fact, when Donald Trump said recently that the UK "should leave," it probably hurt the exit cause more than it helped it. Trump's comments about barring Muslims from entering the United States continue to cause great consternation in the UK, where 5 percent of the population is Muslim. Boris Johnson himself described those comments as "extraordinary" in a recent interview with CNBC, and quickly distanced himself from any possible comparison to Trump (his hair aside!).
Many commentators have pointed out the ways that U.S. and UK politics have moved in tandem over the years (Reagan and Thatcher, Clinton and Blair etc). However, I do not believe a Brexit vote will alter the likelihood of a Trump victory in any way whatsoever.
There will be parallels to draw and observations to make, perhaps the most interesting of which will be found in the percentage of the left of British politics — supporters of Labour, the Scottish National Party, and the Green Party — opt to vote for an exit. Might this provide clues to the extent to which Sanders supporters will decide to desert the Democratic party and vote for Trump? Maybe at the margin.
But for the most part, even that would be an inference too far. Part of the reason Labour supporters are backing Brexit is because it hurts their arch enemy, David Cameron, and the Conservative party. Thus, just because supporters of both Donald Trump and Bernie Sanders may oppose free-trade agreements does not mean that they are driven by the same sentiments as those Brexiteers an ocean away.
Commentary by Wilfred Frost, co-anchor of of "Worldwide Exchange." Follow him on Twitter @WilfredFrost.
For more insight from CNBC contributors, follow @CNBCopinion on Twitter.
