[johnfernow]

Some fair points. Courts have ruled Congress can make laws concerning foreign residents that would be unconstitutional if applied to domestic residents and citizens. They generally can't deny someone their Constitutional rights once already inside the US though. But since deportation isn't a criminal conviction (and rejection at the border especially isn't), it's conceivable that they could deny someone entry for a variety of reasons.

So perhaps not a violation of the Constitution. Though if the scientist's claims that he was denied entry because he expressed a personal opinion on the Trump administration's research policy, then it certainly violates the spirit of the First Amendment, and much of what the government claims it stands for. Is it legal? Perhaps. Will it cause long-standing damage to US soft-power and the ability of US organizations to recruit world-class scientists? Quite possibly.

[cryptonector]

> Some fair points.

Thanks.

> Though if the scientist's claims that he was denied entry because he expressed a personal opinion on the Trump administration's research policy, then it certainly violates the spirit of the First Amendment, and much of what the government claims it stands for.

That's an "if". We don't know what the CBP agent saw. But let's assume it's harmless, then I agree that it's damaging to the Administration's brand, but I also wouldn't agree (yet) that it happened because of Trump's orders.

> Is it legal? Perhaps.

Current law gives the executive branch the power to turn away foreigners for almost any reason.

> Will it cause long-standing damage to US soft-power and the ability of US organizations to recruit world-class scientists? Quite possibly.

Almost certainly, especially if neither CBP makes a more useful statement nor the WH comes out and clears things up. It's entirely possible that the WH will not take notice and that CBP doesn't want to engage the public on this.

Some years ago the Texas Alcoholic Beverage Commission started going into convention venues in Texas and arresting anyone they could argue was publicly intoxicated. That led to a spate of conventions boycotting the state until the TABC backed down.