A lot of people are linking the candidacies of Bernie Sanders and Donald Trump under headings like “populist” and “anti-establishment.” Most of these comparisons are too cute for their own good — not only because it’s too early to come to many conclusions about the campaign, but also because Trump and Sanders are fundamentally different breeds of candidates who are situated very differently in their respective nomination races.

You can call both “outsiders.” But if you’re a Democrat, Sanders is your eccentric uncle: He has his own quirks, but he’s part of the family. If you’re a Republican, Trump is as familial as the vacuum salesman knocking on your door.

Consider the following. We’ll start with some of the more superficial differences between Sanders and Trump and work our way to the more important ones.

1. Trump is “winning” (for now), and Sanders isn’t. There are lots of reasons to suspect that Trump will fall from his position atop the GOP polls sooner or later, but he’d be a favorite to win a hypothetical national primary held today. Sanders, by contrast, trails Hillary Clinton by about 20 percentage points in national polls that include Joe Biden, and by 30 points in polls that don’t.

2. Sanders is campaigning on substantive policy positions, and Trump is largely campaigning on the force of his personality. I’m not sure this assertion requires a lot of proof, but if you need some, check out the candidates’ websites. Sanders’s lists dozens of specific policy proposals across a wide range of issues; Trump’s details his position on just one, immigration.

3. Sanders is a career politician; Trump isn’t. Let’s not neglect this obvious one. Bernie Sanders has been in Congress since 1991, making him one of the most senior members of Congress; Trump has never officially run a political campaign before.

4. Trump is getting considerably more media attention. Trump is a perpetual attention machine who gets a disproportionate amount of media coverage — as much as the rest of the GOP field combined. Sanders hasn’t been ignored by the press, which wants a horse race between Sanders (or Biden, or anyone!!!) and Clinton. Still, Sanders’s media coverage has been paltry compared with Trump’s. According to Yahoo News, Trump has received about 35,000 media “hits” in the past month, compared with about 9,000 for Sanders. For comparison, Clinton has had 18,000 hits over the same period, and Jeb Bush has had 14,000.

5. Sanders has a much better “ground game.” Trump, in addition to his ubiquity on television, has some semblance of a campaign operation. But Sanders’s organization is much larger and more experienced.

6. Sanders holds policy positions of a typical liberal Democrat; Trump’s are all over the place. While Sanders doesn’t officially call himself a Democrat — a fact that might annoy Democratic elites — he takes policy positions that are consistent with those of Democrats in Congress. In the previous Congress (113th), Sanders voted the same as liberal Democratic senators Barbara Boxer, Cory Booker, Kirsten Gillibrand and Sherrod Brown 95 percent of the time or more. He voted with party leader Harry Reid 91 percent of the time and the expressed position of President Obama 93 percent of the time. He also voted with Clinton 93 percent of the time when the two were in the Senate together.

Here are the senators Sanders voted with most and least often in the 113th Congress, according to Voteview.org:

SENATOR MOST OFTEN SENATOR LEAST OFTEN Boxer (CA) 96.2% Manchin (WV) 82.1% Markey (MA) 95.9 Baucus (MT) 87.4 Booker (NJ) 95.8 Pryor (AR) 87.6 Cantwell (WA) 95.8 Donnelly (IN) 89.9 Leahy (VT) 95.7 Hagan (NC) 90.0 Gillibrand (NY) 95.7 Heitkamp (ND) 90.2 Brown (OH) 95.7 Lautenberg (NJ) 90.6 Hirono (HI) 95.4 Tester (MT) 90.6 Menendez (NJ) 95.4 Landrieu (LA) 90.6 Stabenow (MI) 95.4 Reid (NV) 91.4

Trump’s positions are harder to pin down — and he doesn’t have a voting record to evaluate — but he has far more profound potential differences with the Republican orthodoxy on major issues ranging from taxation to health care to reproductive rights.

7. Sanders’s support divides fairly clearly along ideological and demographic lines; Trump’s doesn’t. So far, Sanders has won a lot of support from white liberals — which helps him in Iowa and New Hampshire — but not so much from white moderates or non-white Democrats. Each of these groups represents about a third of the Democratic primary electorate nationally, so this makes Sanders’s path to the Democratic nomination fairly easily to analyze; he’ll be viable only to the extent that he gains support among the other two groups.

Trump’s support, by contrast, is fairly evenly spread across a range of demographic and ideological groups that appear in Republican polls. He doesn’t do especially well (or especially poorly) with “tea party” voters, for instance. There are a variety of ways to interpret this — perhaps, even, the “Trumpen proletariat” is a group all its own.

8. Sanders’s candidacy has clear historical precedents; they’re less obvious for Trump. Even the most formidable-seeming front-runners haven’t won their nominations without some semblance of a fight. Clinton’s position relative to Sanders is analogous to the one Al Gore held against Bill Bradley in the 2000 Democratic primary. Sanders’s campaign also has parallels to liberal stalwarts from Howard Dean to Eugene McCarthy; these candidates can have an impact on the race, but they usually don’t win the nomination.

Trump has some commonalities also: to “bandwagon” candidates like Newt Gingrich and Herman Cain; to media-savvy, factional candidates like Pat Buchanan; and to self-funded candidates like Steve Forbes. None of those candidates, however, was as openly hostile to their party as Trump is with Republicans.

9. Trump is running against a field of 16 candidates; Sanders is running against one overwhelming front-runner. Trump is also in new territory in another respect. There’s never been a Republican nomination race — or for that matter a Democratic one — with so many declared candidates. Most of the Republicans are not tokenish candidates either. All but Trump, Ben Carson and Carly Fiorina have served as senators or governors before, many of them in highly populous states.

This unprecedented volume of candidates helps Trump in various ways. For instance, it increases the value of differentiating yourself from the field. Unorthodox or even unpopular policy positions may help you win a faction of the Republican electorate, even if it makes you less popular within your party overall. That faction may be enough to carry the plurality in polls, leading to favorable media coverage and then creating a virtuous cycle that attracts some bandwagon voters.

Meanwhile, the abundance of candidates seems to have resulted in the Republican establishment holding off on throwing its support to any one candidate, either through endorsements or in the money race.

The Democratic establishment, by contrast, has never been so united behind any non-incumbent candidate as they are with Clinton.

10. Trump is a much greater threat to his party establishment. It would be a mistake, however, to conclude that Sanders is as threatening to the Democratic establishment as Trump is to the Republican one. Sanders’s policy positions, as I’ve mentioned, are about 95 percent the same as those of a typical liberal Democrat in Congress. And where they diverge, they push Democrats further to the left in a fairly predictable way, acting as a “supersized” or slightly exaggerated version of the Democratic agenda. Indeed, while Sanders lacks support from elected Democratic officials, he has some backing from other influential constituencies within the party, such as some labor unions and liberal media outlets.

Why, then, have so few Democrats officially endorsed Sanders? First, because Clinton is extremely popular with both elite and rank-and-file Democrats. Her relative lack of competition is a sign of strength, not weakness — she won the “invisible primary” stage of the campaign. Second, because Democrats are right to be concerned about the general election prospects for Sanders, a 74-year-old self-described socialist. Third, because Sanders’s agenda is hostile to moneyed interests within the Democratic Party.

But if Sanders eventually overtook Clinton, the establishment might resign itself to the prospect of nominating him. There are some loose precedents for candidates like Sanders winning their nominations, especially George McGovern in 1972 and Barry Goldwater in 1964. If you’re going to sacrifice a presidential election — and Sanders would be unlikely to prevail next November — you’d at least like to shift the window of discourse in your party’s preferred direction.

A Trump nomination would be more of an existential threat to the Republican establishment. He bucks the establishment’s consensus on issues as fundamental to the GOP as taxation and health care, and he’s wobbly on abortion. Splitting with the party on any one of those issues might ordinarily disqualify a candidate. Trump potentially destabilizes the Republicans’ “three-legged stool”: The coalition of fiscal, social and national security conservatives have dominated the party since 1980 or so. But on the issue on which Trump is most conservative — immigration — establishment Republicans worry that he might be so reactionary as to cause long-term damage to the party brand.

Meanwhile, Trump has picked fights with sacred cows like the Club for Growth and Fox News. Most of the conservative media — from the National Review to RedState to Glenn Beck — is anti-Trump.

In certain respects, Trump is engaged in an attempted “hostile takeover” of the Republican Party. Because the downside of nominating him might be so enormous — lasting beyond a single election — the GOP establishment may fight to the death to prevent him from being chosen, even at the price of a brokered convention and a fractured party base.

What Sanders and Trump have in common is they’re both unlikely to be nominated. (If I were laying odds, I’d put either one at something like 15-1 or 20-1 against.) But it’s for different reasons. Sanders is losing now, but if he eventually overtakes Clinton — and if Biden fails to come to the establishment’s rescue — his position might become more viable. Trump is nominally winning, but the GOP race is much more volatile. And if he doesn’t lose steam on his own accord, the Republican establishment will use every tool at its disposal to stop him.

Check out our live coverage of the second Republican debate.