The Note: Democratic Fight Night in Wisconsin

— -- NOTABLES

--SANDERS AND CLINTON GET READY TO RUMBLE: Hillary Clinton and Bernie Sanders will share a stage tonight at the University of Wisconsin-Milwaukee for their sixth debate of the campaign. The two are meeting for the first time since the New Hampshire primary and Iowa caucuses in a debate hosted by PBS News. Moderators for tonight’s debate are NewsHour co-anchors Gwen Ifill and Judy Woodruff. The debate kicks off at 9 p.m. Eastern. There’s more on the line tonight than there ever as the Democratic race has turned into a real dogfight, ABC’s VERONICA STRACQUALURSI notes. Sanders is fresh off his historic win and after her stinging loss, Clinton is expected to fight aggressively.

--THE BIGGEST TAKEAWAY FROM NEW HAMPSHIRE: Perhaps the only surprise Tuesday night was Bernie Sander’s competitiveness among nonwhites and mainline Democrats. A further thought this morning, sparked by Rick Klein, was to look at those groups by age. Voilà: It’s about those pesky youngsters. Overall, as we’ve reported, nonwhites in New Hampshire divided evenly, 50-49 percent, Clinton-Sanders. That was unexpected, given that nonwhites have been among Clinton's strongest groups in national polls. ABC’s NEWS ANALYSIS DESK has more. http://abcn.ws/1T83qwu

--LOOKING AHEAD: ABC’s PAOLA CHAVEZ and VERONICA STRACQUALURSI have five things to know about how New Hampshire changed the race leading into the next contests in Nevada and South Carolina. http://abcn.ws/1QW9Ah2

--ANALYSIS -- ABC’s RICK KLEIN: Yes, Hillary Clinton has a big, enormous, ridiculous lead among superdelegates. No, this is not necessarily the best time for her campaign to be bragging about that fact. According to ABC’s delegate count, Clinton currently leads Bernie Sanders 394-44 among delegates, despite her blowout loss in New Hampshire and only the narrowest of wins in Iowa. Clinton campaign aides are touting that lead, at least implicitly, in arguing to supporters and donors that the delegate math is overwhelmingly in her favor. That, though, makes a few dangerous assumptions. First, it presumes that if superdelegates matter, they would openly deny the nomination to someone who won more delegates via actual voting. (Remember 2008, anyone?) Second, and more urgently, it presumes that Sanders supporters won’t wake up to this possibility and use it as motivation. A line about how the establishment is trying to subvert the judgment of the people could slip rather easily into a Sanders stump speech.

YESTERDAY ON THE TRAIL with ABC’s PAOLA CHAVEZ and VERONICA STRACQUALURSI