Perceived by whom? And which Christians?
I have a rule of thumb that I've found very useful. What's more, I've gotten some very enthusiastic responses when I've presented it to others. The thing is that it really does model my emotional reactions quite well.
If someone tells me they're a "Christian" -- or have been "born again" -- within the first half hour of conversation, that's a very bad sign. I tend to have a very negative impression. If, on the other hand, I'm surprised after some days -- or weeks or years -- to discover that someone is also a church-going Christian, I generally take that as a positive thing.
Naturally, it doesn't work in every context. If you first meet the guy in a conversation about religion at a party, for example, all bets are off.
I think we all need to take a moment and read his original post again. He is talking about Christianity's dominant place in America vs, the minority status of Muslims, and how he feels that Liberals tend to defend the underdog. Here is his post, I see nothing about what Christians do, or how they are perceived, beyond they're being perceived as the dominant religious force in America (which of course, they are, that is inarguable):
Many people often ask the question why are Christians picked on more than Muslims or other religions.
Part of the liberal mindset is to defend those who are perceived as weak and attack those who are strong.
One of the main reasons this is done is to deny the false dichotomy of Christianity = good. Islam = bad.
Christianity is followed by a huge majority of our population. It is a fixture of American society and is not threatened in any way by criticism. In general it is viewed in a positive light by most Americans. Some like myself seek to dissuade people from thinking the Christianity is a big rosy picture that is ideal. It isn't.
Islam on the other hand due to recent events is generally villified in our national conscious. We watch the news about terrorists and fanatics in the street shouting death to America and buring American flags.
We have created a good guys vs. bad guys scenario and things are never that simple. Liberal minded people tend to favor a grey view of things saying something is not pure good or evil.
I can assure you that if you transplanted many of the liberal posters here who attack Christianity and defend Islam over to the middle east they would be doing the reverse.
Pretty much it is the seeking to moderate views that is responsible for the anti-Christian pro-Islam impression many have.