Rand will get out of Brennan what the hearings couldn't get out of Hillary. Rand will watch Hagel's everystep through his Committee assignments.
He's picking the right battle with Brennan.
He could have filibustered Hagel and it would have been over. You have to omit he went along and personally said "the President can appoint anyone he wants to appoint. However, there is no where in the appointment clause of the constitution where the President has the sole power to appoint anyone he wishes.". It is up to congress to make the final decision.
Watching his step does not mean the shoes are already dirty. There is a 54 to 46 majority what is he going to do?