Noise and controversy aside, Donald Trump is making two arguments about immigration. The first is that the U.S. admits too many immigrants. The second is that, given nearly two decades of Islamic terrorism, the government should take special measures to keep out Muslim immigrants who might threaten safety and security.

Trump made both points at his recent rally in Greensboro, N.C. Here's how he made the first: "We've admitted four times more immigrants than any other country in the world. We can't do this. We can't do this. Not surprisingly, real wages haven't increased for 18 years. And then they wonder why I have packed houses."

Critics quibble with Trump's "four times" point, arguing that more sophisticated ways of counting would yield a different result. But Trump's point stands: the U.S. has admitted more immigrants than any other country, and by any reckoning admits a lot of immigrants.

Here's how Trump made the second point: "Just so you understand — I have many Muslim friends. These are amazing people. They're great people. The problem we have is, whether it's 7 percent or 9 percent or 11 percent or 1 percent — we're having a tremendous problem in our country. We don't know — there doesn't seem to be assimilation — we don't know what's going on."

That was a considerably less clear argument for the most controversial part of Trump's agenda, commonly known as the Muslim ban. (More precisely, a proposal to temporarily bar foreign Muslims from entering the United States.)

Trump's talk about percentages refers to Muslims who believe that suicide bombings or other terrorist killings are justified in the name of Islam. In recent days, Trump has referred to extensive studies done in the last five years by the Pew Research Center on Muslim attitudes worldwide and in the U.S.

Among the many, many questions asked by Pew was this: "Some people think that suicide bombing and other forms of violence against civilian targets are justified in order to defend Islam from its enemies. Other people believe that, no matter what the reason, this kind of violence is never justified. Do you personally feel that this kind of violence is often justified to defend Islam, sometimes justified, rarely justified, or never justified?"

Pew found that 81 percent of the nearly 3 million Muslims in the United States said such violence is never justified. Five percent said it is rarely justified; 7 percent said it is sometimes justified, and 1 percent said it is often justified. Six percent said they didn't know.

One can read those numbers reassuringly — 81 percent disavow jihadist violence — or one can read them alarmingly. Trump reads them alarmingly. If Pew's numbers are correct, then 13 percent of the Muslims currently in the United States believe Islamist violence is justified in at least some cases. Given the current Muslim population of the U.S., that's just under 400,000 people.

In any case, events of the last year have shown that there are definitely Muslims who believe in violent jihad already in the United States. The question Trump asks is whether the U.S. should add more. "The media talks about 'homegrown' terrorism, but Islamic radicalism ... and the networks that nurture it, are imports from overseas," Trump said in his much-criticized national security speech on Monday. "Yes, there are many radicalized people already inside our country as a result of the poor policies of the past. But the whole point is that it will be much, much easier to deal with our current problem if we don't keep on bringing in people who add to the problem. And that's what we're doing."

Trump pointed specifically to the American-born Orlando killer Omar Mateen, whose parents came from Afghanistan. (In delivering the speech, Trump mangled the part of his prepared text that said Mateen "was born to Afghan parents who immigrated to the United States.") "[Mateen's] father published support for the Afghan Taliban, a regime which murders those who don't share its radical views, and they murdered plenty," Trump said. "The father even said he was running for president of Afghanistan. The bottom line is that the only reason the killer was in America in the first place, was because we allowed his family to come here."

There's no doubt that many Muslims in Afghanistan (which is 99 percent Muslim) believe Islamist violence is justified. Pew found that 18 percent of Afghan Muslims said such attacks are often justified, 21 percent said they are sometimes justified, and 18 percent said they are rarely justified — for a total of 57 percent who believe Islamist violence is justified on at least some occasions. (Forty percent said such attacks are never justified, and 3 percent didn't know.)

In addition, Pew found that 99 percent of Muslims in Afghanistan favor making Sharia "the official law of the land in our country."

And yet, as Trump said in the national security speech, "Immigration from Afghanistan to the United States has increased nearly five fold in just one year." (In a fact check, PolitiFact confirmed Trump's statement, noting, "The United States granted legal permanent resident status to 2,196 Afghans in 2013, and 10,527 in 2014, according to the Department of Homeland Security. That's about five times as many in one year.")

Trump's national security speech was the most extensive case he has made recently that the U.S. should not admit large numbers of immigrants from Afghanistan and other countries with high belief in Islamist violence and Sharia law. "They share these oppressive views and values," Trump said. "We want to remain a free and open society."

But what about the Muslim ban? Trump's speech led some to conclude he had abandoned that proposal in favor of a country-by-country plan. But he had not.

"I called for a ban after San Bernardino and was met with great scorn and anger," Trump said in the national security speech. "But many are saying that I was right to do so. And although the pause is temporary, we must find out what is going on. We have to do it."

Instead of dropping the Muslim ban, Trump grafted onto it a country-by-country addition: "When I'm elected I will suspend immigration from areas of the world where there's a proven history of terrorism against the United States, Europe or our allies until we fully understand how to end these threats."

So what now? Trump knows the Republican electorate that gave him the nomination strongly supports the Muslim ban. To cite a few examples from exit polls, 69 percent of GOP voters in the Pennsylvania primary supported the ban, while in New York, the number was 68 percent, in Wisconsin, 69 percent, in Florida, 64 percent, in Georgia, 68 percent, in Ohio, 65 percent, and in Texas, 67 percent. That's essentially two-thirds support across the Republican primary electorate.

On the other hand, Trump is in a general election environment now. And it appears he might be making some sort of transition to a new Muslim proposal, to refine the original Muslim ban into a radical Islam ban, in an effort to appeal to a wider electorate while not losing primary voters. The essence of governing is compromise, Trump might argue, and while he still believes in his original proposal, he knows there is substantial opposition. So here is the compromise: a ban on immigration from X countries and areas of the world with substantially radicalized populations.

It seems unlikely Trump would lose much of his current support with such a move. And he would gain, at least, among Republicans who have favored a country-by-country approach. (Ted Cruz, for one, proposed a country-by-country ban during the primaries.)

The Muslim ban proposal has set off near-hysterical reactions among both Democrats and some anti-Trump Republicans. The people who have called him bigoted, hateful, a Nazi, un-American, and more are not likely to calm down if Trump were to refocus his proposal. But Trump, supported by current events — the Orlando shooter's family just happened to come from one of the worst countries in the world in terms of Muslim radicalization — could reset the debate just the same.