HOA liens are "super liens"! They go in front of first position mortgage, so they can foreclose the bank out, so the bank has a choice, pay off the lien with interest or loose their lien. Same with back property tax liens. Hope that helps.
In many instances Ron is correct.... HOA liens can be superior, but only when purchasing the lien rights to collect the outstanding debt. If you were to purchase that debt from the lienholder, you will be repaid for the face value of the debt plus an lawful interest and legal fees.
However, in Florida for instance, when a successful bidder buys a HOA lien at a foreclosure auction, they get title subject to the existing mortgages and other junior encumbrances. This is a good thing when the sum total of the outstanding liens are less than market value of the property. However, the OP clearly states the properties are underwater. Therefore, it would not make sense for the purchaser to payoff the existing mortgages.
Superior liens or not, when an HOA lien is paid of at a foreclosure auction, the successful bidder now owns the property subject to the inferior lien-holders. Since these are paid off, they cease to be a lien and therefore are no longer superior. Plus, you cannot put a lien on something you now own, so that money used to purchase the lien is now gone.
This is why both Eddie and me believe the investor buying these up must be renting out the property in order to make a profit. He may also have inside information which allows to take such a large gamble.
you and the homeowner and show them why its advantageous to short sale. Call me if I can help - http://ForeclosureProcess.net