In the Denver Post, Barrie Hartman wrote a couple of years ago:
A lot of you apparently grew up as I did. As a Christian, you believed that more could be accomplished with love than with hate. What mattered was helping the downtrodden and loving your fellow man. Now, with a blurred definition of Christianity, you can't be a true believer without being devoted to a war that is worth nearly 1,000 American lives (so far) because my God is better than your God.
In my view, we mainstream Christians have sunk to a new low by allowing, in our silence, the religious right and our government to use Jesus and the church as political pawns to validate an unnecessary war. ... From Niwot: "I, too, despair that Christianity and religion are becoming pseudonyms for patriotism and Godliness. We have a wonderful minister. But beneath this man and the congregation's exterior facade, there lurks homophobia, steadfast loyalty to the war, and an inability to adjust to any view not consistent with Biblical revelations. There is no room for using your God-given intellect."
I can agree with Harman that when Christians fail to speak up against extremists, they become complicit in what those extremists do — the same is true within Islam and any other ideological movement, be it religious or secular. I'm not sure, however, that the label "hijacking" is appropriate here. Using it allows one to dismiss others too easily and, in the end, is what allows such extremism to exist.
A person can be said to "hijack" an airplane if they meet certain requirements: they take, through force, authority and power over the airplane which they do not and should not have. A terrorist hijacks an airplane through the use of actual or threatened violence and because there is absolutely no warrant for their having authority over the operation of direction of that plane, either from the airline or from the passengers.
Does any of this apply to those who are claimed to have "hijacked" Christianity? I don't think so. In contrast, a pilot who was a passenger and who assumes command after the regular pilot falls ill does not hijack the plane because no violence is involved and because, even though proper authority was not explicitly given to them, no other choice was available. It is also arguable that a person who simply says that they wish to take command of the airplane and then does so after little or no argument from the passengers or crew is hardly a hijacker.
It is true that intimidation has been used in some cases by conservative Christians in their ascent to power (for example, within the Southern Baptist Convention), but by and large the assumption of power and authority has been entirely peaceful. Is there any reason to say that they have no just claim to power and authority? There might be if their doctrines had no basis in historical Christianity or Christian scriptures, but that isn't the case.
The beliefs promoted by conservative evangelicals and fundamentalists may not be the only way to view Christianity, but there is no way to reasonably argue that they aren't presenting a historically and doctrinally legitimate view of Christianity, however unpleasant it might be at times. Sure, they pick and choose which aspects of Christian tradition to emphasize, but the exact same thing is true of moderates and liberals.
The reason why labeling them as "hijackers" is so problematic is that it ignores this very basic point. In dismissing their legitimate claims to the Christian tradition, it pretends that Christianity doesn't really contain the seeds of extremism, intolerance, violence, and authoritarianism. Those aspects of Christianity cannot, however, be adequately confronted and dealt with by Christians unless and until they acknowledge that it is all part of their tradition.
Barrie Hartman is, then, playing the old game of "the bad parts of Christianity are all due to the efforts of outside hijackers, not 'true' Christians who are the 'real' insiders." It's "us vs. them," an old saga often used in order to explain way a group's errors, faults, and failings. This tactic never really succeeds, however; instead, it only allows the problems to fester and continue. What's worse, it's just the sort of tactic which extremists themselves use to such great effect. This means that in his efforts to deny that extremists are "true" Christians, Barrie Hartman is playing the extremists' game right along with them.
If people like Hartman want to get anywhere, they need to acknowledge that the conservatives and fundamentalists are embracing legitimate aspects of the Christian tradition and then explain why those aspects should not be embraced (or at least not embraced in that particular manner). Christians must acknowledge that they are following not a perfect belief system, but a belief system full of flaws and with a history of intolerance and violence. The point should be to teach believers how and why they should rise above all that, not that if they are "real" Christians they won't fall victim to problems at all. The former is a tactic that teaches caution, humility, and skepticism. The latter is a tactic that teaches people to be self-righteous and over-confident.