From Parker's April 18 column:

Is the political environment becoming so toxic that we could see another Timothy McVeigh emerge?

No one knows the answer, but fears that anger could escalate into action beyond the ballot box are not misplaced. Ninety-nine percent of angry Americans might be perfectly satisfied to rail at their television sets -- or to show up at a Tea Party rally -- but it takes only one.

The biggest concern for security folks in Washington is the lone operator, the John Hinckley, who tries to take out a president for his fantasy girlfriend. Or some variation thereof.

This is why “Don't retreat. Reload,” Sarah Palin's recent imperative to her Tea Party audience, felt so off. Obviously, she wasn't suggesting that people arm themselves, as she has explained several times since. Hunting and military vocabulary are hardly new to politics. We “target” audiences or “set our sights” on policies and politicians all the time. In the world of healthy competition, trophies are victories, not dead people.

But words matter, as we never tire of saying. And these are especially sensitive times, given our first African American president and unavoidable fears about the worst-case scenario. If Jodie Foster could bestir the imagination of Hinckley, a Sarah Palin in the Internet age could move regiments.

[...]

All of the above have put the nation ill at ease. Add to the mixture of organic anger and grass-roots momentum the heckling language of Beck, Limbaugh & Co., and one fears that volatility could become explosive. What's next, militias?