AT&T, the world’s largest telecom company with assets of $446 billion, is no longer a member of the American Legislative Exchange Council (ALEC).

AT&T’s exit from the corporate bill mill follows Verizon’s decision to leave in mid-September, based on ALEC’s choice of hatemonger and anti-Muslim David Horowitz to headline a session at its annual meeting in New Orleans promoting the corporate lobby group’s radical plan to rewrite the U.S. Constitution.

Now AT&T is cutting ties for the same reason. “We have ended our membership with ALEC and their convention speaker was a key factor in the decision,” Jim Greer, AT&T’s spokesperson, said in a statement to The Intercept. The Intercept also reports that Dow Chemical and Honeywell have left ALEC.

The Center for Media and Democracy’s report of Horowitz’s bigoted remarks at the ALEC meeting inspired a coalition of 79 democracy reform, civil rights, and advocacy organizations to send a letter of protest to ALEC’s largest corporate backers, including AT&T, urging them to “make it clear that [they] will not stand for the sort of toxic, inflammatory claims ALEC has embraced” and depart ALEC.

AT&T has long held a seat on ALEC’s Private Enterprise Advisory Council, and was a regular high-level sponsor of its meetings.

The back-to-back departures suggest that telecom giants are concerned about the impact ALEC’s extremist policies and associations will have on their brand-sensitive customer base. Sprint left ALEC in 2012 after public uproar over ALEC’s promotion of controversial voter ID and “Stand Your Ground” legislation, and T-Mobile departed in 2015 amid a backlash against ALEC’s climate denial stance. That leaves Comcast, Charter Communications, CenturyLink, and Cox Communications as the last major telecom companies sticking with the corporate bill mill.

Comcast and Charter are Director Level sponsors, and CenturyLink a Trustee Level sponsor, of the 2018 States & Nation Policy Summit in Washington, D.C. this week.

“AT&T’s exit just further proves that ALEC is becoming too toxic for mainstream corporations to be affiliated with. Other telecom companies, like Charter and Comcast, must follow AT&T and Verizon’s lead and cut ties with ALEC,” said Jay Riestenberg, Deputy Communications Director at Common Cause.

More than 110 corporations and 19 nonprofits have severed their ties with ALEC in recent years. If ALEC continues to embrace extremists like Horowitz, it will likely see more companies head for the exits.