This move is likely to cause tax revenues to drop and real estate values to collapse.

The proposed change imposes a 4% surtax on residents with taxable income of $1 million or more. Currently, the state income tax rate is a flat 5.1%. So, when the measure comes into effect in 2019, the wealthiest taxpayers in Massachusetts will see their state income tax burden nearly double, which will cause many of them to move elsewhere.

Before the surtax comes into effect, it must be endorsed at a constitutional convention and approved by state voters. But judging by the lopsided votes for approval in both chambers of the legislature, the amendment being passed seems a foregone conclusion. The state Senate voted 33–7 in favor of it; the House vote was 102–50.

Why would seemingly intelligent elected officials enact a law that is almost certain to result in a lower standard of living for Massachusetts residents?