Donald Trump's proposed ban on Muslim immigrants sounds an awful lot like the Islamic State's religious litmus tests, Hillary Clinton suggested Thursday.

"Really, ever since the pilgrims landed on Plymouth Rock, America has distinguished itself as a haven for people fleeing religious persecution," Clinton said at a campaign even in Reno, "believing in religious freedom, and religious liberty."

"Under Donald Trump," she said, "America would distinguish itself as the only country in the world to impose a religious test at the border. Now, come to think of it, there actually may be one other place that does that: The so-called Islamic State. The territory that ISIS controls. What a cruel irony that someone for president would equate us with them."

Her comments came as she warned supporters that a Trump presidency would pose a serious and real threat to religious freedom in the United States.

"He'd ban Muslims around the world from entering our country just because of their religion. Now think about that for a minute. How would that actually work?" Clinton asked.

The Democratic candidate continued, and maintained her focus on the issue of Trump's proposed Muslim ban and its implications for the idea of religious liberty in the United States.

"So people landing in a U.S. airport would line up to get their passports stamped, just like they do now. But in Trump's America, when they step up to the counter, the immigration officer would ask every single person, 'What is your religion?' And then what? What if someone says, 'I'm a Christian,' but the agent doesn't believe them? Do they have to prove it?" she asked. "How would they do that?"