Um… no.
All my adult life, I've been hearing variations on the theme of "the modern persecution of the Christians." (That exact phrase cropped up on AM talk radio in Austin, Texas back in the mid 1980s.) Anyone who actually believes this is displaying both a staggering ignorance of early Christian history and a staggering ignorance of current American cultural dynamics. I suppose it's a very comforting, self-valorizing narrative for some people, but that doesn't make it true.
Christianity is still overwhelmingly privileged in this country. Despite explicit Constitutional declarations to the contrary, our government is overwhelmingly Christian. 89.3% of the members of Congress are Christian. (8.4% are Jewish, the rest are other or undeclared, with only one openly declared atheist.) Although I can't readily find similar statistics for Federal judges, I strongly suspect they're quite similar. Likewise most state and local governments. We celebrate major Christian holidays as secular holidays — when was the last time you got Hannukah or Ramadan off at work? We see a constant privileging of Christian ideals in education, in law making, in local, state and federal government. (If you want to talk about being under attack, atheists, by contrast, often poll as the most despised group in this country.)
So far as I can tell, what some Christians interpret as attacks on religion are a combination of two things.
One is the constant drumbeat from conservative politicians and media alleging such attacks. Fox's "War on Christmas" is an example of this effect. Those declarations are almost always severely divorced from reality, but in conformance with the principles of the Big Lie, they are repeated so often and so loudly that many people come to believe their truth. (Especially people who have a significant psychological investment in seeing themselves as persecuted heroes.)
The other is the gradual lessening of the absolute grip of Christian privilege on our society. Christianity is merely overwhelming these days, as opposed to utterly dominant. Moves to restrict school prayer and government display of nativity scenes may feel like attacks to Christians, but what they are in fact is some daylight for people of other faiths and no faith at all.
Confidential to Christians in America, and especially Christianists: Not getting things your way all the time doesn't count as persecution. It's a rebalancing that acknowledges other strands of the culture.
Speaking from the outside of a Christian framework, that Christians see themselves as under attack is laughable. In many major debates in our culture, self-identified and high profile Christians are the aggressors, for the most part without any worthwhile moral basis. Everything from reproductive rights to teaching good science in the schools to marriage equality finds large groups of vocal Christians and their prominent political and spiritual leadership arguing vociferously for regressive repression and standing firmly on the wrong side of history. Just as many Christians stood on the wrong side of history with Bible-based beliefs on slavery and Civil Rights movement, a historical irony that seems utterly lost on Christianists arguing today against everything from gay rights to access to contraception under the rubric of "religious freedom".
My friend's unconscious assumption that their faith is under siege is very telling about how deeply that meme of persecution has sunk into the minds of the very same people who are daily working to limit the rights and freedoms of so many of my fellow citizens, and stunt the education of all our children. To my Christian friends: if you want to be taken seriously by people outside your own faith narrative, open your eyes and look at what people are doing in the name of you and your God.
(And no, I did not engage this question at all on the mailing list. It was off topic, and it would have been deeply rude of me. I address it here with anonymity out of respect for the source, and because I think the question is important.)