It’s hard to overstate how wonderful is the news that Prime Minister Boris Johnson has won a mandate to, after all these years of struggle, lead a restoration of British sovereignty and independence. We may have been in that fight from the early days, but we don’t mind saying that we’ve had moments of doubt, particularly during the past year, that Britain would prevail. All the sweeter the results being tallied this evening.

This is only partly in respect of Brexit. It was, certainly, the overriding issue in the election. It is the very reason why the election was called when it was. Once again, the polls got it wrong. On the eve of the vote, the gods of polling were predicting that the race had become too close to call. A hung parliament couldn’t be ruled out. Some hazarded that Labor’s Jeremy Corbyn might end up at 10 Downing Street.

In the event, the British people delivered a resounding “no” to all that Mr. Corbyn stood for — the resentment of Jews and Israel, the embrace of socialism, and another Brexit referendum. The result is that Labor’s drubbing stands as its worst since 1935. No less than Jonathan Chait rushed out a column to mark that American leftists thought Corbyn’s inevitable victory would be their model against Trumpism.

Which is one way to mark a phenomenon that has been glimpsed throughout this battle since 2016. The phenomenon can be put this way: “As goes Brexit, so goes Trump.” In a way, the Brexit referendum turned out to be a predictor, or even a precursor, of Mr. Trump’s triumph in the election. The victory by Mr. Johnson and the Conservative Party today could well be a precursor of Mr. Trump in 2020. On verra.

Not that the Sun is in a mood to take anything for granted. We’d rather eat a jellied eel. Mr. Johnson and the Conservatives now have an unambiguous mandate, not only from the direct democracy of the 2016 Brexit referendum but also in Parliament. That, though, doesn’t mean that the wiley Europeans are going to take this lying down, as was clear from a recording leaked to the Independent on the eve of the election.

In the recording, the EU’s chief negotiator, Michel Barnier, can be heard boasting, or warning, that the negotiations with Britain can’t be accomplished in the next eleven months. Aaaargh, ga vargle. It’s a reminder of how atrociously the Europeans have comported themselves in this drama. And of what a strategic error Prime Minister May and Prime Minister Johnson made to seek a negotiated departure. Better a hard Brexit all alone.

It would be nice to think that this vote finally puts Europe on the spot. Mr. Barnier’s bombast came before the election. Some of the Europeans are starting to recognize that they have lost the game and will finally be facing a Parliament that is aligned with the decision of the British voters in 2016. As if to underline the point, the British pound soared on news that the Conservatives had won a mandate for Brexit.

The right thing for President Trump — who has understood this drama better than any Democrat — is to get a trade deal with the British done with dispatch. And to focus on expanding the principles of political economy that began to be articulated in England and Scotland and have powered the greatest eras of liberty and prosperity. And for him to remember those principles in our own political battle in the coming year.