We'll never know what Qaddafi's forces might have done in Benghazi had they reached there. But we do have some data on the shelling of Misurata:

Human Rights Watch has released data on Misurata, the next-biggest city in Libya and scene of protracted fighting, revealing that Moammar Khadafy is not deliberately massacring civilians but rather narrowly targeting the armed rebels who fight against his government. Misurata’s population is roughly 400,000. In nearly two months of war, only 257 people — including combatants — have died there. Of the 949 wounded, only 22 — less than 3 percent — are women. If Khadafy were indiscriminately targeting civilians, women would comprise about half the casualties.

That number is roughly confirmed here:

Doctors say more than 240 people have been killed and over 1,000 wounded in Misurata in the last month, as Gaddafi's forces have sought to retake the opposition bastion.

All of this is horrifying. But remember Dennis Ross' claim that 100,000 could be killed in Benghazi? Yes, Benghazi was even more of a symbol of the resistance than Misurata, but the discrepancy here is simply fantastic. Did we go to war on false, scare-mongering pretenses? That could never happen in America, could it?