What drives liberals and democrats into apoplexy is calling their sacred cows into question: the entire holy trilogy of Great Society, Medicare and Social Security. Raise even minor problems with these and you can watch their blood pressure increase by the second. The yelling starts, discourse is shut down and only by silencing their opponents can they start to recover their composure. It makes it hard, at times, not to tease, since you can get them so riled up with little effort.
This is a great example of how these folks react to criticism. It's a capture of a certain point in time, a point in time where the original author decided that she had enough lip and removed the comments. Read and see how she utterly fails to make her point and gets taken down.
Of course, there's more to the story than that. The woman involved is Froma Harrop, She is the President of the National Council of Editorial Writers and runs the Civility Project, designed to improve the quality of political discourse: in other words, shutting down discourse is an epic fail.
Read the comments - where there is no cursing and no ad-hominem attacks - and understand what liberals mean when they demand an end to incivility: they are really demanding an end to anyone talking back to them.
It is the sound of sacred cows being gored. They are losing, slowly, gradually, but consistently, their world picture of how the world should be working. They are the do-gooders and can do no wrong (and have done so much wrong that it will take a generation to fix it); they are the smart ones that everyone should listen to (whose ignorance is legion and legendary); they are the ones who understand how to make peace (and end up make wars not only possible, but inevitable); they are the ones sympathetic to the down-trodden and the disadvantaged (but exploit these groups in order to have a good life for themselves); they are the ones who will remake the world so that it is just and fair (but lack the understanding that there is no such thing in the real world and that by taking from others to give to others, they are just as unjust and unfair).
I could go on. R. Emmett Tyrell Jr. wrote a lovely book called "The Liberal Crack-Up" back in 1984. You could call it the disintegration of principled liberalism into trendy enthusiasms without principles.
Now the sacred cows of liberalism are being gored. It will get much uglier out there than anyone really wants to see, and that is the hope of the liberals: they want to shut anyone up who disagrees.