Theoretically it's possible since tax liens are, generally, superior to all other liens. However, practically it is not likely unless there are no mortgages on the property. Most mortgage companies are going to pay the tax lien rather than allow the owner of the tax lien to foreclose and lose their entire investment. It does happen, I personally know of at least one instance where it DID happen, but it is extremely rare.
Tax liens can be a very good investment since interest rates are set by the local government and usually command a high rate of interest. However, the most likely outcone is the owner of the tax lien will be paid the lien and the interest due on it.