In the Republican presidential primary in New York, the Sun urges a vote for Senator Ted Cruz. It hasn’t been our normal practice to endorse in the primaries, but this year the vote, set for Tuesday, will take on outsized importance as we career toward a contested convention. The junior senator from Texas has emerged from a crowded field by dint of his fidelity to principles — limited, constitutional government, sound money, free markets, and a strong foreign policy — that couldn’t be at higher premium. They are the true New York Values.

Our endorsement is not animated by hostility to either Donald Trump or Governor Kasich, both of whom are running well ahead of Mr. Cruz in the polls in New York. All three are better on key issues than either Secretary Clinton or Senator Sanders. We like Mr. Trump’s willingness to re-think the United Nations. We’re not against better trade deals. We are against a retreat from NATO, and Mr. Trump has been too xenophobic in his use of language in respect of religion and the immigration issue. Mr. Cruz, a former solicitor general of the border state of Texas, has been more sage.

The first thing we are looking for, in any event, is a candidate who grasps, is committed to, and is excited by America’s constitutional principles. The Constitution ought to be a unifying instrument; it is, after all, the only thing that all of our legislators, officers, and judges — from the President to the county sheriffs — must be bound by oath to support. Our ideal candidate is someone who thinks in constitutional terms and who references and reveres the principles in our national parchment.

On this head, Senator Cruz laps the field. He has done a better job than any other Republican at building a constitutional approach. He has also done a better job on the economy, though we wish that all candidates in both parties would grasp that the bitterness over illegal immigration into America can be permanently addressed only by economic growth. It is not the abundance of labor that has stunted our progress but rather the dead hand of government upon our economy.

Mr. Cruz has put forth a more principled approach to taxes than another fine senator, Marco Rubio. Mr. Cruz’s flat tax is more strategic, more equitable, more pro-growth. Both Mr. Cruz and Mr. Trump would seek the cuts in corporate taxes that have exiled to foreign countries trillions of dollars in corporate reserves. But Mr. Cruz has been far ahead of any other candidate in marking what for us is an essential element restoring American growth and employment — monetary reform.

The Texan was the first to declare for sound money. He did this in the Republican debate in Colorado, when the question was put by Rick Santelli. Mr. Cruz declared that the Federal Reserve “should get out of the business of trying to juice our economy and simply be focused on sound money and monetary stability, ideally tied to gold.” Mr. Trump, too, has spoken, en passant, of the virtues of the gold standard. But Mr. Cruz has been actually pursuing monetary reform within the Senate.

Congress’s work on this is an under-reported story. The Fed Oversight Reform and Modernization Act, the most important monetary measure since the American retreat from sound money in the 1970s, passed the House in November, within days of Paul Ryan acceding to Speaker. It is now before the Senate, where Mr. Cruz was already a sponsor of a constituent part of the bill, Audit the Fed. If Congress does move to restore a sound dollar, history will show that Mr. Cruz was present at the creation.

On foreign policy, Mr. Cruz has been better than any Democrat — or Mr. Trump, who, in our view, is hobbled by his early opposition to the Iraq war. We’re well aware that, on this head, ours is a minority view, but there it is. The world is far better off today without the Baathist tyranny we toppled. The error was not President Bush’s in leading the democratic nations into Iraq but President Obama’s in withdrawing. It’s been more than 70 years since World War II and our GIs are still needed in its theaters.

In respect of the Middle East and the war being levied against us in the name of radical Islam, the first battle that needs to be won is that between the White House and the Congress. Both Messrs. Trump and Cruz would be highly effective on this front, but it is Mr. Cruz who more clearly grasps the constitutional nature of the affront by President Obama. This emerged in administration’s plunge into the appeasement of Iran while being opposed by majorities in both houses of Congress.

The American Founders rejected a king. Their republican vision was a democracy in which the business of government is conducted by elected delegates, who are accountable to the law, tempered by an independent judiciary. Millions of Americans sense that the Democrats have become unmoored from the constitutional principles. Mrs. Clinton would re-write the First Amendment; New York, in 1788, ratified the Constitution only on the caveat that a Bill of Rights would be included. Those are the true New York values, and Mr. Cruz has been the most faithful to them in the current campaign.