This big.

It’s hard to compare one primary contest to another.

Each race has its own dynamics, and the 2008 contest among then-senators Hillary Clinton, Barack Obama and John Edwards was as different from this year’s race as the 2000 election between vice president Al Gore and former New Jersey senator Bill Bradley.

But if there’s one thing that we can compare, it’s the margin of victory between the first-placed candidate and the second-placed candidate. Exit polls showed that 12% more of the electorate considered themselves ‘liberal’ than the 2008 Democratic electorate, for example, an effect of growing political polarization that surely boosted Vermont senator Bernie Sanders into landslide territory.

But it was a landslide by this measure. The only primary victory that comes close to Sanders territory was then-Massachusetts governor Michael Dukakis’s win in 1988 en route to the nomination (but not, alas, the presidency). 

In some cases, like in 1992, Bill Clinton, then governor of Arkansas, essentially ‘won’ New Hampshire by exceeding expectations. In retrospect, hardly anyone thinks of the real winner, then-senator Paul Tsongas, as a true threat for the 1992 nomination.

But it’s striking that, with 66% of the vote counted, Sanders is leading by a  22% margin. If that holds, it will be easily the largest margin of any contested New Hampshire primary in the modern era, when presidential nominations have been decided by primary contests and not at party conventions.

It’s a far larger margin than those enjoyed by then-president Jimmy Carter in 1980 (facing a challenge from Ted Kennedy) and by then-president Lyndon Johnson in 1968 (facing a challenge from anti-war candidate Eugene McCarthy). In Johnson’s case, the scare in New Hampshire was enough to cause him to drop his bid for reelection altogether.

Sanders had something of a home-state advantage as a longtime official from neighboring Vermont. But it wasn’t enough to stop Clinton from holding a lead in New Hampshire as recently as early December, and it wasn’t enough to rejuvenate Vermont’s then-governor Howard Dean in 2004 (though he lost to another ‘neighbor,’ Massachusetts senator John Kerry).

Of course, there’s a lot of reason to believe that tonight’s contest was the high-water mark of the Sanders campaign, and the primary calendar gets much, much tougher for Sanders in the weeks ahead, when he’ll face a far more diverse electorate that, for now, seems to favor Clinton.