Former Florida Gov. and 2016 Republican presidential candidate Jeb Bush is lambasting Democratic front-runner Hillary Clinton after a progressive group released a new ad criticizing his defense of brother George W. Bush and how he handled the Sept. 11 terror attacks when he was commander-in-chief.

Bush tweeted to Clinton on Sunday, “Your political machine’s 9/11 ad is disgraceful. As a New Yorker you know the leadership my brother provided after 9/11.”

The GOPer was referencing a 30-second spot from the group “Americans United for Change,” which is not affiliated with Clinton (although the group shares president, Brad Woodhouse, with pro-Clinton super political action committee Correct the Record).

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The ad, called “Safe?”, focuses on Bush’s comments during last week’s Republican presidential debate, in which he defended his older brother’s national security strategy, arguing “he kept us safe.” The line earned him applause, but the new ad suggests the former president did not keep the country safe from “a crumbling economy,” “bureaucratic catastrophe” and “unnecessary war.”

Woodhouse said in a statement about the ad, “It’s as if Jeb Bush believes his brother’s presidency began on Sept. 12, 2001. But we’re not letting Jeb rewrite history.”

Bush has had to strike a balance of respecting his family legacy while also proving he’s a leader who would make his own decisions.

Clinton’s campaign did not immediately respond to a request for comment about Bush’s latest criticism.