Bob's exactly right - set aside your knee-jerk reaction and put Rand's endorsement in perspective. Your heart will still likely reject it but your mind may see the wisdom in it.
Consider too that this is likely a trial balloon to Ron himself endorsing Romney during his convention speech. Jack Hunter is making the case that Rand's endorsement doesn't change his principles and is necessary to the movement's success. Those same arguments apply doubly to Ron's endorsement. It's the biggest chip Ron has on the table in negotiating with Romney for policy changes and administration influence. Don't expect him to throw it away because a few people might get emotional. If he can endure 40 years in the wilderness he can certainly endure whatever his misguided supporters may say for a few weeks.
So the next time your anger swells at Rand, imagine your reaction if Ron had just endorsed Romney instead. Because this was done entirely with Ron's knowledge and approval and will not end with Rand.