Unlike most Republican candidates, Donald Trump has repeatedly promised that he will protect Social Security and Medicare as they exist currently. He has subjected his contenders who have proposed changing the two major entitlement programs to withering criticism.

He has in turn been criticized by Republicans and conservatives for promising pie-in-the-sky solutions to voters and ignoring the demographic trends that threaten Social Security. Trump has dismissed such concerns by promising that the economic growth his presidency would usher in would keep the system solvent.

But AARP, the most prominent and consistent opponent of attempts to fully or partially privatize Social Security, says that Trump’s promises to maintain entitlements aren’t good enough.