Maddow is not "cluelessly attacking Rand Paul". She's making sure the liberal sheep don't wander out of the Democratic political agenda. Supporting Rand Paul on an issue where principle progressives would agree with a "teabagging Republican" would be hurt the Democratic Party.
Maddow's only role is to pen up the "progressive" activism for the Democratic party. For goodness sakes Obama appeared at a Nutroots convention, said two words, and literally played a propaganda clip of Maddow praising his "accomplishments" while any progressive knows he was a sell out.
Once you ask "Is it good for the Democratic Party?" you'll realize that Maddow is far from clueless in what she does.