That sucks.
Bear in mind, though, that NO, you and your brother don't "have to bail them out." Remember that if you spend too much of your own money, time and energy on them, you'll be shortchanging not only yourself, but eventually your own spouse and kids. If you spend a lot bailing out your parents, you're just passing the buck--eventually your own kids will have to bail you out, or at least you won't be able to provide for them as you should (e.g. paying for college if they don't get a scholarship), because you spent so much taking care of your parents that you didn't have enough left over to take care of yourself, your spouse and kids! If the situation is really dire--if the parents are beyond reason and keep digging themselves into financial holes--then instead of bailing them out, the higher duty is to make sure that problem STOPS with their generation. You'll be doing your kids, grandkids etc. a great favor.
Personally I think that the only obligation we should feel towards our parents is to literally keep them off the streets and, if they need medical care or something along those lines and aren't able to get it, to help them get it (whether at home or in a nursing home). And I don't primarily mean help them financially by paying medical bills--I mean, for instance, helping them get signed up with Medicare supplemental insurance, helping them find a good doctor who takes their insurance, etc.
What I mean by "keep them off the streets" is that even if you feel obligated to help your parents, you're not obligated to help them maintain their desired lifestyle. If their financial problems are putting them at risk of foreclosure, for instance, it makes no sense to pay their late mortgage payments to bring the house out of foreclosure if in fact they cannot afford that house on their own dime. If that's the situation, then they can't afford that house and need to let go of it, even though letting go will no doubt be painful and embarrassing for them.
Even if they're losing an unaffordable house there no doubt IS something they CAN afford, though, so maybe you help them look at listings for much cheaper houses, maybe you offer $X towards their down payment on a place they can actually afford (and if you do so you should get a lawyer to draw up docs making you an X% owner of the house), maybe you help look at rental listings (and offer to help with the deposit if need be), maybe you help them apply for public housing if they qualify, maybe you pitch in and help them move or offer to provide $X to cover part or all of their moving costs (if they're as money-dumb as you describe, it is WAY safer to say "I'll pay your moving company $2000 towards the cost of your move" than "I'll pay for your entire move" or "I'll give you $2k for your move," for obvious reasons... such as that if you pay them instead of the moving company the money could vanish, and a move that should cost $2k may end up costing twice that if they insist on moving all their crap instead of getting rid of what they don't need before the move).
I guess the shortest way to describe this advice is, even if you feel greatly indebted to your parents and even if you want to help save them from themselves, NONE OF THAT includes ANY obligation to help maintain their self-destructive lifestyle (i.e., no obligation to help them keep the baubles they've acquired--fancy house, extra car, whatever). It only includes an obligation to keep them from being literally homeless... in other words, an obligation to help them get a roof over their heads that they can afford, and only IF their situation becomes so bad that if you don't step in with some help, they'll become homeless.
And I'm not some heartless Libertarian or whatever. My sibling and I each pay half of our mom's mortgage every month--but then, the reason she needs that is not because she spent her life making idiotic financial decisions. She spent her life working her ass off but she's been severely physically disabled since we were kids, so there was only ever so much she could do to earn money; she managed to raise us, but not to save for retirement.
And by the way, for everything I said above, I'm talking about non-abusive parents here; to those who were physically or emotionally abusive, you have no duty at all.
Also by the way, none of this will necessarily be possible. If your parents or one of them is alcoholic, or psychotic and won't take their meds, etc., sometimes it's not even possible to keep them off the streets because our country provides very little in the way of legal mechanisms to control how adults choose to live their lives.