Here are highlights of some recent, reliable polls on Supreme Court term limits:

Harstad Research (for Fix the Court):
Asked the question two ways to 802 primary voters Feb. 26 to Mar. 4, 2015:

1. Do you support term limits for the justices serving on the U.S. Supreme Court? 66% favored; 29% opposed
2. Do you support term limits for the justices serving on the U.S. Supreme Court, instead of the current lifetime appointments? 60% favored; 37% opposed

(Full polling memo here.)

Penn Schoen Berland (for C-SPAN):
Asked the question two ways to 1,201 adults July 1-6, 2015:

1. Do you support ending life tenure? 60% said yes; 40% said no
2. Would you support a plan whereby the justices served an 18-year term with possible reappointment? 79% said yes; 21% said no

Reuters:
Asked this question to 1,611 adults July 10-17, 2015:
Do you support a 10-year term limit for Supreme Court justices? 66% said yes; 17% said no

Fox News:
Asked this question to 1,019 adults July 13-15, 2015:
Should Supreme Court justices serve for only a limited time? 72% said yes; 25% said no

McLaughlin & Associates (for the Coalition of Court Transparency):
Asked this question to 1,000 likely voters Aug. 4-8, 2014:
Should we abolish the practice of lifetime appointments for Supreme Court justices and instead allow justices to serve only a fixed term? 71% said yes; 21% said no