The next Constitutional crisis?

From the tone, though not the substance, of this NY Times article today, it's beginning to sound as if the first really big clash between Congress and the Prez is going to be over Monica Goodling. It seems she may be planning to not even attend the Congressional session to which she's been subpoenaed, based on her intention to take the 5th. That, of course, is not the way it works. You are obliged to attend. During your attendance you may take the 5th, but an intention to take the 5th. does not excuse a failure to attend.

Should she fail to attend, Congress could hold her in contempt, but contempt citations are enforced by the Department of Justice, which might well refuse to enforce it. Then, under its inherent powers, Congress could dispatch the sargent at arms and the Congressional police to arrest her, but what would happen if they confronted a phalanx of FBI officers protecting her from arrest?

Constitutional crisis in the making.