The Overton window is an approach to identifying which ideas define the domain of acceptability within a democracy's possible governmental policies. Proponents of policies outside the window seek to persuade or educate the public in order to move and/or expand the window. Proponents of current policies, or similar ones, within the window seek to convince people that policies outside it should be deemed unacceptable.

Some of the biggest pro-Bernie Sanders groups on Facebook were briefly taken down Monday evening in a targeted attack by Hillary Clinton supporters.

The groups Bernie Sanders Activists, Bernie Believers, BERNIE OR BUST, Bernie Sanders Revolutionaries, Bay Area for Bernie, Bernie Sanders 2016 — Ideas Welcome, Bernie Sanders is my HERO, and Bernie Sanders for President 2016 were all taken down in the attack. The pages in question were reported to be down for about three hours, from 9 p.m. to midnight Monday night.

Collectively, these groups are home to more than a quarter million Bernie Sanders supporters, and some have been in existence for nearly a year, having been launched shortly after the Vermont senator declared his intent to run for president in 2015.

The groups were targeted by online trolls, who posted pornographic images and reported the groups to Facebook admins. Some legitimate Bernie supporters even reported seeing images containing pedophilia, according to reporting from Heavy.com.

IN THE FINAL DAYS leading up to Maryland’s Democratic voters going to the polls on Tuesday to choose their U.S. Senate nominee, Rep. Donna Edwards has been barraged by ads and mailers from the Super PAC backing her opponent, Rep. Chris Van Hollen, called the Committee for Maryland’s Progress.

A television ad assails Edwards as “one of the least effective members of Congress,” contrasting her career with Van Hollen’s legislative record. It mentions no foreign policy issues, despite the dominant issue motivating one of the Super PAC’s largest funders.

Recently released disclosures reveal that $100,000 — a sixth of what the Super PAC has raised —comes from a single source: a donation by pro-Israel billionaire Haim Saban.

A “One-Issue Guy”

Saban, who made his fortune in the media and entertainment industry, has spent millions of dollars influencing the foreign policy establishment, including by sponsoring the Brookings Institution’s Saban Center for Middle East Policy and funding the American Israel Public Affairs Committee (AIPAC). He is also one of the largest donors to Hillary Clinton’s Super PACs. In a 2010 interview with the New Yorker, he described himself as a “one-issue guy, and my issue is Israel.”