MI SB0280

Establishes that initiative petitions must be filed with the secretary of state at least 160 days before the election at which the proposed law would appear on the ballot.

Requires petition filers to sort signatures by congressional district and provide a written good-faith estimate of signature counts from each congressional district when filing with the secretary of state.

Limits signatures used to validate petitions to no more than 15% from any single congressional district, with excess signatures not counted toward petition sufficiency.

Requires the board of state canvassers to complete canvass of initiative petitions no later than 100 days after filing or 100 days before a general November election if filed at least 160 days beforehand.

Specifies that a referendum petition becomes properly invoked when the board of state canvassers makes its official declaration of sufficiency, at which point the subject law ceases to be effective.