First Read is a morning briefing from Meet the Press and the NBC Political Unit on the day's most important political stories and why they matter.
HEMPSTEAD, NY -- Well, we're finally here: Hillary Clinton and Donald Trump tonight square off in their first presidential debate at Hofstra University, making it arguably the most consequential night so far of the 2016 election. The stakes are enormous, with recent polls showing the national race ranges from a six-point lead for Clinton (in the NBC/WSJ) to a dead-even tie (in Bloomberg's). There are five storylines we're watching heading into the debate.
Which Donald Trump shows up? After observing him over the last 15 months, including during the GOP debate season, we're pretty confident who Trump is -- he's aggressive, loaded with zingers and oppo hits, and shaky on policy. But there the possibility that a different Trump could show up tonight. But if we were in Las Vegas, we'd bet heavily on the Trump we know showing up. (Just see Trump's Gennifer Flowers tweet from over the weekend.)
Which Hillary Clinton comes to play? Meanwhile, we've spent the last eight years watching Clinton at presidential debates, and she's good. (Remember, she's a former lawyer.) Clinton was at her absolutely best last October in that first Democratic debate, where she ran circles around Bernie Sanders and her other opponents. But Clinton also has had some uneven performances -- think of that Democratic debate in Iowa right after the Paris terrorist attacks. And there was her game-changing rough moment when Tim Russert asked her about drivers' licenses for undocumented immigrants in Oct. 2008.
How does Trump fare in his first one-on-one debate? That's right. Tonight will be the first time that Trump has ever debated an opponent one-on-one. Indeed, he thrived (and sometimes simply survived) during the GOP debate season with as many as eight to 10 other Republicans on the stage. So even though he was always in the spotlight, he only had to speak 12-18 minutes in a two-hour debate. Tonight will be different.
How does Clinton fare in facing off against the ultimate Alpha Male? In his preview of tonight's debate, the Atlantic's James Fallows interviewed the famous anthropologist Jane Goodall. "In many ways the performances of Donald Trump remind me of male chimpanzees and their dominance rituals," Goodall said. "In order to impress rivals, males seeking to rise in the dominance hierarchy perform spectacular displays: stamping, slapping the ground, dragging branches, throwing rocks. The more vigorous and imaginative the display, the faster the individual is likely to rise in the hierarchy, and the longer he is likely to maintain that position." How Clinton responds could be one of the most important parts to tonight's debate.
What happens in the first 30-40 minutes? As Politico's Shane Goldmacher observes, history has shown that most memorable moments of a debate typically happen early. "That's when Al Gore first sighed, Mitt Romney knocked President Obama on his heels, and Marco Rubio, earlier this year, glitched in repeating the same talking point — over and over and over. It's when Gore tried, unsuccessfully, to invade George W. Bush's space, Richard Nixon was first caught wiping away sweat with a handkerchief (during the moderators' introductions!) and Gerald Ford in 1976 made the ill-advised declaration that, 'There is no Soviet domination of Eastern Europe.'"
Do the debates really matter?
That's the fascinating question our colleague Dante Chinni asks. And his answer: not really. "Looking at pre-debate NBC News/Wall Street Journal presidential polls and the final election results since 1992, there is only one campaign where the debate may have made a serious difference — 2000. In every other case, the candidate that led going into the debates wound up winning on Election Day. And, to be fair about 2000, Democrat Al Gore actually did get more votes than Republican George W. Bush (but lost the Electoral College), so technically — where the popular vote is concerned — the numbers above show a perfect 6 for 6. The candidate that led in the poll going into the debate period won the election." On the other hand, 34% of voters in our new NBC/WSJ poll said that debates will be either "extremely important" or "quite important" in deciding their vote. Also, don't be surprised if the third-party vote in polls starts to drop after tonight. And how that vote gets distributed in the post-debate polls will be important to watch.
Playing the expectations game
NBC's Alex Seitz-Wald and Benjy Sarlin tee up tonight's debate. "The good news for Trump, Republicans say, is that the expectations for his performance are about at rock bottom. While he's been more a more disciplined campaigner in recent weeks, he's struggled to stay on message and answer substantive policy questions. He also has never faced the bright spotlight of a one-on-one debate. His campaign, looking to reinforce his underdog image, claims he's eschewing typical debate preparations... Clinton, meanwhile, faces sky-high expectations. She's an experienced debater, having participated in nearly 40 debates since her first campaign for senate in New York 16 years ago, and has been holding marathon prep sessions at a debate camp set up in a hotel near her Chappaqua home."
The skinny on tonight's debate
The debate starts at 9:00 pm ET, and it lasts 90 minutes - divided into six 15-minute segments. Clinton gets the first question of the debate (on the result of a coin toss). About 1,000 audience members will be in attendance, and they are encouraged to remain quiet. We've got everything else you need to know about all the presidential debates, all in one place -- nbcnews.com/debates.
On the trail
Tim Kaine campaigns in Florida, making stops in Lakeland and Orlando… And Mike Pence holds a rally in Milford, NH at 1:30 pm ET.
Countdown to VP debate: 8 days
Countdown to second presidential debate: 13 days
Countdown to third presidential debate: 23 days
Countdown to Election Day: 43 days