I predict that in the next tax reform - in about 25 years - the mortgage deduction will disappear. It could not in the last round a few years back because so many people use it, but the standard deduction is now so high that most states only the filthy rich can use it and so most voters won't care. (sorry bay area residents, but your property values are something the rest of the country laughs at)
Actually a lot of people can still use it if they pay for points on a mortgage. The upfront cost of the points is treated as mortgage interest for tax purposes.
