It's pretty clear that he wants to establish a Muslim database or at the very least is very open to the idea, and I've read that analysis.

"'Do you think we might need to register Muslims in some type of database, or note their religion on their ID?'

'We’re going to have to look at a lot of things very closely. We’re going to have to look at the mosques. We’re going to have to look very, very carefully.'"

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"'Should there be a database or system that tracks Muslims in this country?

'There should be a lot of systems," Trump responded. "Beyond databases. I mean, we should have a lot of systems.'"

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In this last quote he is unambiguously being asked about a full Muslim database, not a database of immigrants.

"'Let's hear it directly from you," said host Kimberly Guilfoyle. "Would President Donald Trump support a full Muslim database?'

'Basically the suggestion was made and (it’s) certainly something we should start thinking about'"

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Establishing a Muslim database is clearly a civil rights violation. Trump says "we should start thinking about it". He says we should start thinking about something which is clearly a civil rights violation, so I don't think it's a stretch at all to be afraid that he may actually harm civil rights.

>That's not a logical progression at all. The United States has no obligation to let anyone into the country.

The police also have no obligation to protect any particular person, but when they refuse to protect someone based on their religion, it becomes a civil rights violation.

I understand that this is a matter for the courts do decide and it isn't actually a clear cut civil rights violation, but a quick google search shows at least a few respected legal scholars who believe that a ban on non-citizens based on religion would violate the constitution http://www.msnbc.com/msnbc/harvard-professor-laurence-tribe-...

"According to several scholars surveyed by MSNBC, while foreign citizens do enjoy fewer rights than Americans, it is still illegal for the government to use a religious test on foreigners. The Constitution's 'bar against declaring an official religion' would apply to discrimination against non-citizens, argues Harvard law professor Laurence Tribe."

"Cornell Law professor Michael Dorf said that while U.S. policy 'routinely applies different immigration rules for nationals of different countries,' Trump’s proposal to only exclude 'foreign nationals who are Muslim' would likely be 'unconstitutional.'"