Another point of clarification for this thread is that the mortgage interest deduction is for *new* mortgages, not existing ones.
According to my math a middle income family of 4 would have to be taking itemized deductions of over 30k in the old system to not be saving money on this proposed tax break using the increased standard deduction and new rates and bracket.
You mean the $500,000 limit, because there is NO cap on existing mortgages.