O'FALLON, Mo. (AP) — The effort by Sen. Josh Hawley and others to challenge Democrat Joe Biden’s election victory is a “radical” and “highly destructive attack," former U.S. Sen. John Danforth said Monday.

The written statement from the 84-year-old three-term Republican senator was especially stinging since Danforth has long been a supporter of Hawley, publicly backing his successful run for Missouri attorney general in 2016 and his 2018 Senate bid, when he defeated incumbent Democrat Claire McCaskill.

Hawley was the first Republican senator to say he would join with several House Republicans in objecting to state Electoral College tallies. Since then, 11 other Republican senators and senators-elect have joined President Donald Trump’s effort to overturn the November election.

“Lending credence to Trump’s false claim that the election was stolen is a highly destructive attack on our constitutional government,” Danforth, of St. Louis, said in a written statement. “It is the opposite of conservative; it is radical. As one friend asked me, ‘What are my grandchildren to think of America if they are told that elections are fraudulent?’

“At a time of extreme polarization the populist strategy is to drive America even farther apart by promoting conspiracy theories and stoking grievances,” Danforth said. “We must reject this strategy and reclaim America’s historic purpose of holding our diverse nation together as one people.”

An email message left with Hawley’s office wasn’t immediately returned.

Danforth has criticized Trump’s efforts to overturn the election. He said that by alleging widespread fraud, Trump sought to “undermine Americans’ belief in the legitimacy of the election and therefore in the foundation of our democracy. He is causing incalculable damage to our country.”