Setting aside the details of what Trump is offering up, there's a political question that's worth answering here: Does Trump's harder line on the ban and on Muslims actually do him any good for November?
Trump's proposal, introduced as a temporary ban but on Monday extended until we have a "perfect" way of screening new entrants, has been broadly opposed by Americans since Trump first brought it up in December. It was a response to the mass shooting in San Bernardino, Calif., a few days earlier, and quickly prompted questions about ethics and practicality. How, after all, does one effectively screen something that's intangible? But, as with so many other aspects of Trump's unusual campaign, it moved quickly from shocking to just another thing.
While most Americans in December didn't approve of the ban, there was a split by party. Two polls, one from Quinnipiac University and another from NBC News and the Wall Street Journal, showed Democrats broadly opposed to the idea but Republicans more mixed. Independents, as is usually the case, fell somewhere in the middle — in part because "independents" are mostly a mix of people who still basically affiliate with one party or the other.
Trump got some validation, though, during the primaries. As contests were finished and exit polls became available, we learned that nearly 70 percent of Republican voters, on average, approved of the idea of a ban on new Muslims entering the country. But not all of those voters actually backed Trump. More did as the contests moved forward (since there were fewer candidates from whom to pick). In every state but Texas and Wisconsin, Trump got most of the votes. But in the states for which we have exit polling, an average of a third of those who came out to vote (a) backed the ban but (b) didn't vote for Trump.
In other words: That's one group of people to whom doubling down on the ban might appeal. But, then, a lot of those people have likely already moved to support Trump in general election polling. What's more, the electorate in a party primary is normally not terribly reflective of the overall pool of voters in the general.
In April, PRRI asked again about the idea of a ban. It found that attitudes hadn't changed much since the last time they surveyed, but it also weighted responses by party and by how strongly respondents felt about the issue.
Two-thirds of Americans opposed the ban — a third of them strongly. Keep in mind, this was a few weeks after the bombing in Brussels, so terrorism hadn't really moved to the back burner. More than two-thirds of independents opposed Trump's proposal. Among Republicans, more than a third approved of the idea, 16 percent strongly. But, interestingly, Trump supporters themselves were about evenly split. Forty-nine percent supported the idea; 46 percent didn't.
A good sign that this isn't a winning issue for Republicans is that Republican leadership has rejected it. On Tuesday, House Speaker Paul D. Ryan (R-Wis.), who has grudgingly endorsed Trump, said that the ban is not "reflective of our principles."
Most members of political parties end up voting for their party's candidate — more so in 2012 than at any point prior.
So the question mark here is probably independents. Independents generally align with one party or the other, including in a presidential race. (According to the book "The Gamble," 90 percent of Democratic-leaning independents backed Obama in 2012.) Perhaps Trump's rhetoric about Muslims more broadly will help expand his base?
The best we can say is: maybe. Last December, The Post and ABC News surveyed Americans and asked if they thought that mainstream Islam encouraged violence or was mostly peaceful. More than half of independents said Islam was mostly peaceful, although the percentage was down from when we asked the same question in 2010. That year independents were 30 points more likely to call Islam peaceful. In 2015, the spread was 21 points.
Perhaps more to the point, a February Pew Research poll asked people how many Muslims in the United States harbored anti-American sentiments. There's no data for independents in particular, but more than half of Republicans and Republican-leaning independents and three-quarters of Democrats and Democratic-leaning ones said only some or "a few" did so.
Trump's obvious goal is to parlay justifiable nervousness over the Orlando attack into political advantage. And by "obvious," we'll point to this retweet from Trump early Sunday afternoon.
To do that, though, he's targeting what appears to be a slice of the electorate, much of which already supports him. It's not clear that there are many people out there who aren't Republican, aren't already supporting Trump and harbor enough antipathy to Muslims to be swayed by Trump's arguments. Those numbers could change — but, at least on the ban, they haven't changed much since December.
In other words, the arguments Trump repeated on Monday were ones that were good for the Republican primary. It's not clear they're very good for the general.