[Bob Wills is still the king]

If you’re a strict Constitutional constructionist, all initiatives, referendums, and other direct democracy applications are unconstitutional, since the Constitution guarantees each state a “republican form of government” in Article IV; Section 4.

“The United States shall guarantee to every State in this Union a Republican Form of Government, and shall protect each of them against Invasion; and on Application of the Legislature, or of the Executive (when the Legislature cannot be convened) against domestic Violence.”

[Brian Griffin]

Imagine if we lacked Amendment II.

The Bill of Rights is evidence that legislative (and executive and judicial power) must be limited. See Amendments I, IV, and VIII respectively.

[Brian Griffin]

A majority should not be able force a government to fleece a minority.

A majority of voters should be able to say that’s a bad statute or we can’t bear that additional tax.

If one man (a President) can veto a law, then a majority of voters should have the like ability.

[frog in a pot]

First, please bear in mind my comment was made with regard to the actions of voters at the state level which, of course, is what the underlying article is about.

Secondly, even before the Constitution was adopted it was argued states should retain the right to adopt other republican forms of government and indeed the USSC has since believed so, as does history.

Ergo, my point is that directly restraining the rulers we vote on (in this case denying the right to impose additional taxes) is not prohibited even by a "strict" view of the Constitution. (Just off the top of my head from decades ago.)