Donald Trump, the Republican candidate for president, said Monday that if elected his administration would require the “extreme vetting” of immigrants seeking to enter the country. Barred would be those who “do not believe in our Constitution, or who support bigotry and hatred,” adding, “Only those who … embrace a tolerant American society should be issued visas.”

Trump staff explained this process would involve questioning and investigating potential immigrants to make sure they supported religious freedom, gender equality and gay rights, for example, meaning immigrants who share the views of Republican cultural conservatives need not apply.

This is an improvement over Trump’s earlier Muslim ban, we suppose, though he did say that until his new plan was in place he would, as president, halt all immigration from “the most dangerous and volatile regions of the world that have a history of exporting terrorism.” He did not say what regions that would include.

Bottom line: Trump’s plan is not practical and, even if implemented, would not appreciably increase security on the home front. Any potential immigrant with malicious intent will be sure to provide Trump screeners the answers they want to hear. The nation already has a watch list of individuals of concern who might seek entry.

If Trump truly wants to do some practical vetting, he will release his tax returns as every presidential candidate has done for 40 years so that voters can vet his suitability to administer the most powerful position in the world.

We already know that Trump sees the value of this kind of vetting. Those under consideration to run with him as the vice presidential candidate were asked to supply the Trump campaign with tax returns going back a decade.

As of now, Trump has decided voters are not entitled to the same information about him. He has used the bogus excuse that his recent tax returns are the subject of an IRS audit. There is no legal or practicable reason, however, why an audit should prevent Trump from turning over the records. The returns, while subject to adjustment due to audit, would represent the good-faith effort (we would hope) of Trump and his accountants to present the facts of his income, credits and deductions.

What is more likely going on here is that there are things Trump would just as soon voters not see, not unlike an immigrant who would rather not have U.S. immigration authorities learn about a checkered past.

Maybe Trump did not make as much money as he has claimed or paid little or no taxes. Perhaps his charitable giving is not impressive. Or maybe recent returns would show business with foreign entities (Russia?) that would undermine his America First theme.

The thing is, Trump is running for president and voters deserve to know how a candidate for that office managed finances and tax obligations. If that means taking some lumps, so be it.

There was a time when Trump appeared ready to share the information.

Back in January, “Meet the Press” host Chuck Todd asked the candidate, “Will you release any of your tax returns for the public to scrutinize?"

“Well, we're working on that now. I have very big returns, as you know, and I have everything all approved and very beautiful and we'll be working that over in the next period of time, Chuck. Absolutely,” Trump responded.

Eight months later, voters await the “very beautiful” tax returns.

Bill and Hillary Clinton recently released their joint tax returns for 2015, as the couple has done going back to 1977. They made $10.6 million in adjusted gross income, down from $28 million in 2014. They paid an effective rate of 34 percent last year, about the same as a year before and about 8 percent higher than the average in their income bracket. It was probably a political calculation not to have the accountants search too hard for tax breaks to lower that rate.

They gave about 10 percent of their income to charity.

The income came mainly from speaking fees, books and Mr. Clinton’s consulting work. Did all that speaking money come with strings attached for the would-be president? It’s a fair question, one emphasized by Clinton’s primary opponent, Sen. Bernie Sanders.

But the public does not know what questions or concerns Trump’s returns would raise.

Clinton’s vice presidential candidate, Sen. Tim Kaine of Virginia, also released his returns. Trump’s VP pick, Indiana Gov. Mike Pence, indicates he will, also.

Trump needs to dump the excuses and come clean.