It's happening. The House of Commons voted Friday to move Prime Minister Boris Johnson's Brexit withdrawal agreement bill to the committee stage.

Having won an 80-seat majority in Britain's Dec. 12 election, Johnson will have no trouble moving the bill through Parliament by the final week of January. On Jan. 31, Britain will leave the European Union and, in so doing, will join the realm of self-rule.

The EU might claim to serve the fine ambitions of a safe, pluralistic, and prosperous political alliance. But it is shaped by excessive centralization and government power, and it has eroded the sovereignty of its member states. It is eroding democracy in the name of centralization. More than two years after they voted to leave, Britons are finally getting back the power to govern themselves under laws passed by lawmakers they voted for.

Brexit will restore Parliament to its deserved place of honor. The House of Commons is Britain's supreme legislative body, but EU membership currently requires the Commons to enact rulings from the European political and legal establishment into British law, whether or not Britons support them. Although the principle of parliamentary sovereignty was retained under the EU, it exists only on paper. Had Parliament refused to enact EU diktats, the United Kingdom would have risked sanction. Brexit reestablishes that nothing can dictate the laws and lives of the British people absent the express will of their government and Parliament. This is a change of monumental democratic value.

Britain's government will once again act from the consent of the governed.

Americans take for granted that only U.S. courts set their case law. But in the EU, Britons have long been forced to live under the rulings of European courts. In practice, the restoration of British courts will prevent fishing boats from EU states from fishing out U.K. waters, it will let the British government decide whom to admit for immigration, and it will restore to the British even such basic questions as the age of eligibility for free bus passes. Britain's courts will again have the final say — not those in Brussels, Luxembourg City, and Strasbourg.

Amusingly, Johnson has introduced language to his withdrawal bill that will allow lower British courts to reverse European Court of Justice rulings. The welcome message: Our lower courts have more authority than your highest court.

Brexit will free Britain to pursue trade deals with powerful economies around the world, including the United States. Indeed, Britain's new ability to cut low-tariff, free-trade agreements is one of the fears gripping France's and Germany's leaders. French President Emmanuel Macron recently warned about the risks of an unregulated economic powerhouse on the EU's doorstep. He knows that if Britain makes it easier for the rest of the world to trade with the U.K. than with the EU, the EU might find itself on the losing end of the deal. This is why it's so important for the Trump administration to reach a near-term U.S.-U.K. trade deal.

Britain's post-Brexit prosperity will rest in significant part on Johnson's ability to negotiate a successful deal to govern long-term relations with Europe. If that effort, due to begin on Feb. 1, fails, then Brexit may quickly turn sour in British mouths. We encourage the Trump administration to exert American influence and power to persuade the EU to negotiate generously with Britain.

President Barack Obama once told Britons that if they voted for Brexit, they would have to go "to the back of the queue" for a trade deal. Fortunately, he's out of power, so now both nations can benefit from the deal to come.

It is encouraging to see Britain, the cradle of modern liberty, restore its own self-government. This fix to a democratic deficit is grounds for true optimism going forward.

To the Brits, we say, welcome. Glad you could join us.