Donald Trump, who has skated through much of this campaign on a potent mix of bombast, bluster and talking points grabbed from headlines, finally broke through the ice last night. His lack of preparation for Monday’s debate and his surface grasp of the biggest issues facing this country left voters with an unnerving portrait of a candidate unwilling to do his homework, even at a high-stakes moment.

Hillary Clinton, despite her flaws as a candidate, showed that preparation matters, facts matter. She stayed cool under fire, while Trump foundered blindly when confronted with his flip-flop on birtherism, attempting once again to blame Clinton’s 2008 campaign for one of the most monstrous lies in politics — that President Obama was not born in the U.S. He even praised himself for “forcing” Obama to produce a birth certificate, leaving unaddressed why he continued to whip that falsehood for another five years. What has Trump failed to produce that is of far more import? His tax returns. Especially now, in light of his offhand remark that not paying taxes makes him smart (which makes the rest of us — what, exactly?), voters should demand Trump prove he is no tax scofflaw.

Clinton’s economic plan is filled with traditional Democratic approaches: higher taxes on the wealthiest Americans, jobs programs, improved infrastructure, lowered college costs. They are costly and would have made a fat target for most Republicans. Trump did little with it, perhaps because his own plan for a massive tax cut aimed at the wealthiest, plus heavy infrastructure spending and trade proposals that could touch off a trade war, would fail even more to bear up under scrutiny.

Even Trump’s attacks were shallow, leaving unfulfilled a candidate’s obligation to press the opposition on issues in a way that might reveal weak spots. A more skilled debater, one prepared with facts, could have spent valuable debate time challenging Clinton on the particulars of trade, economics and an “intelligence surge” instead of blathering on about Rosie O’Donnell, whom he apparently believes deserves whatever vitriol he dishes out, and a Miss Universe winner from 20 years ago who had the temerity to gain weight after she was crowned. Worst of all for Trump, he undermined his own case that he is the strong, unflappable leader who can take on changing the system. Confronted with a pillar of establishment politics, Trump folded into a rhetorical mess who couldn’t stay on message.

Clinton’s strongest moment came when she reminded the world that this nation will stand by its treaties and its allies. That was a welcome display of calm, presidential leadership that stood in marked contrast to Trump’s brayings about transforming NATO into the equivalent of a New Jersey protection racket, where U.S. support is tied to your last payment to this country.

There were missed opportunities on both sides, however. With just weeks left in the campaign, there have been far too many rhetorical distractions and relitigation of past controversies and far too little on this country’s economic future, the best way to heal racial divides, and strategies for fighting terrorism here and abroad.

Voters need to hear more about ways to achieve affordable, sustainable health care — which includes controlling costs — and how to educate young Americans without breaking their financial backs. This is a nation with immense resources, but the challenges facing it are just as great.

Security at home and U.S. standing in the world is assured by no one but ourselves. Americans are smart enough and tough enough to handle the truth. They should demand it from the candidates.