Do those freedoms envisioned back when the "west" was still frontier and mail took 3 months to reach Europe still work in a world of Nuclear, Chemical, and Biological weapons? Does it work in a world of suicide bombers, high explosives, and a world in which you can reach any major city in less than 24 hours?
Yes. I believe freedom to be more important than safety to begin with, so such nonsense isn't going to persuade me in the least. Terrorist bogeymen are largely nonexistent to begin with; the threat is highly exaggerated.
Anyway, if I had a choice between risking annihilated and allowing the government to violate everyone's freedoms as it pleases (which is pretty much the current situation), I'd choose the former. I don't care for police states, and I think a world without freedom isn't a world worth living in or even a world worth existing; people who don't like being cattle are probably inclined to agree with me.
I would respect a President more who said, "We need an agency who can spy and record everything for national security. Their job is not to police the nations many laws, it isn't in their charter, so even if they find you cheating on your taxes, they won't tell the IRS. Their sole job is to prevent major threats against the United States from enemies who would seek to destroy our way of life".
I think that would be only slightly better than outright lying, but I wouldn't respect such a president at all. Why would I respect a president who admits openly that they despise the constitution and freedom? I don't respect presidents who lie about the fact that they care about freedom, either.