Americans saw history made Tuesday night when Hillary Clinton became the first woman to become her party’s presumptive nominee for the presidency. That is a moment women in this country have long waited for, and whether Clinton ultimately wins or loses, a milestone to be celebrated.

The night’s primary returns also made clear that Vermont Sen. Bernie Sanders will not become the nominee, despite a remarkable campaign against the longest of odds. After decisively losing four of the night’s six contests — including by double-digits in California — Sanders should bow to the inevitable and begin unifying the party he had hoped to lead.

It would be a shame for a campaign that has brought so much value, energy and vision to the race to end on an embittered note, with Sanders engaged in a futile fight to scuttle the nomination of a candidate who won more states, more pledged delegates and millions more votes than he did.

That Sanders wishes to fight on for his progressive agenda and influence the platform the party will develop at its July convention is understandable. He is expected to set some terms for his cooperation. But dragging Clinton into a two-front war for half of the summer is too high a price and could erode public confidence in elections if he continues to insist — in what is rapidly becoming a denial of reality — that a “rigged system” is the reason for his defeat.

Sanders can accomplish more by working within the party to get his laudable goals on campaign finance and economic equity adopted and to wield what could be sizable influence when he returns to the Senate.

Clinton appears to have found her voice and message just in time, laying out a set of values in her speech Tuesday night that should appeal to the broad spectrum of Democratic voters and even independents unwilling to link arms with Republican presumptive nominee Donald Trump. But she will have to be at her best to take out a man who has shown himself adept at leveling challengers in unconventional ways.

Trump, having wasted what could have been a five-week jump on Democrats while they were still fighting through primaries, appeared a bit chastened by the recent brouhaha over his intimation that a Mexican-American judge, because of his heritage, could not conduct a fair proceeding on Trump’s lawsuit. A decidedly more restrained Trump read his speech from a teleprompter, a device he has derided others for using, attempting to convince supporters that he understood the gravity of the task before him.

Never to be underestimated, Trump pivoted back to the themes that helped fuel his unpredictable rise: the dangers of immigration, free trade and terrorism. The difference now is that he will be expected to defend those positions against a single challenger. If he hasn’t boned up on his policies yet, now would be the time.

The hardest part of this race is about to get underway.