I think you're being a little conservative in thinking the percentage is less than 5. I don't think there is any way of determining just what the percentage would be but I suspect there are far more people who would take more then they need than those who accept what they get as a subsidy.
A lot of military retirees take advantage of the taxpayers by claiming every instance of medical assistance they sought over the careers. And the VA is more than willing to pay it out. Do you know that sleep apnea is common in 75% of men over 50 yet the large majority of retirees get diagnosed before leaving active duty then use it to drive their disability percentage up? I believe sleep apnea rates 10% but what's important here is that when you total up your disability rating and it rises over 70%, you get an additional check each month that can exceed your normal retiree pay.
Although it's obviously different circumstances between welfare fraud and retiree fraud, greed is greed. Unfortunately most people don't look at the big picture and may ease their mind thinking they're only stealing from the government.
I agree drug testing is ridiculous but the money that would fund that should be used to establish government subsidized diners in poor neighborhoods. Anyone can eat there and meals are cheap. Saves a lot of money in food stamps and ensures that food is available to the poor and especially poor children who unfortunately are oft forgotten by those who abuse the system. Poland uses this system and it works quite well. And I ate in one and it was pretty good.
I agree the right grossly exaggerates the amount of abuse but it's a reasonable thought to believe the left doesn't recognize just how big the problem may be