A group in Massachusetts has begun the preliminary steps to circulate an initiative, for a law that would require presidential candidates to reveal their income tax returns. The group presumably will abandon its plans if the Massachusetts legislature passes the same idea. The legislature is in session and has already held a hearing on that bill, SB 365. See this story.
The initiative first needs the signatures of 2.5% of the last gubernatorial vote, which is 64,750 signatures, by December 6. Then the legislature gets some more time to consider the idea. If the legislature doesn’t pass it, then initiative proponents must get another 10,792 signatures, and if they succeed, the measure would be on the November 2018 ballot.