Molly Riley/Reuters
Lawrence Summers
"Why is the Secretary of the Treasury commenting on NFL players exercise of First Amendment rights?" the former Treasury Secretary under President Bill Clinton tweeted. "Mnuchin says President can use whatever language he wants. I guess he thinks racist taunts are ok. Shame on him."
"Steven Mnuchin may be the greatest sycophant in Cabinet history," he added.
Summers' tweets appear to be a reference to Mnuchin's comments on President Donald Trump's attacks on NFL player protests over the weekend.
Trump went after the NFL on Friday night at a rally for Republican Senate candidate Luther Strange. The president suggested that any player that takes a knee or protests during the national anthem should be fired.
"Get that son of a b---- off the field right now, out. He's fired. He's fired!" Trump said.
In an interview on ABC's "This Week," Martha Raddataz asked the treasury secretary if "SOBs" was the type of language a president should be using, regardless of how he felt about the issue.
"I think the president can use whatever language he wants to use," Mnuchin said. "The issue is the topic, okay? I agree with the president - why does the NFL have all these other rules that they enforce, that they fine players? This is about respect for the military, the first responders."
"Is it not about the First Amendment, is it not about their First Amendment rights?" Raddatz asked.
"No, it's not. They have the right to have their First Amendment off the field," Mnuchin replied.
Following Trump's comments on Friday and subsequent tweets reiterating the point Saturday, players across the NFL joined in on the anthem protests before Sunday's games.
Reuters/Eric Thayer U.S Treasury Secretary Steven Mnuchin
Sunday was not the first time Summers has spoken out against Mnuchin.
Back in May, he wrote an op-ed for The Washington Post criticizing Mnuchin telling bankers at Michael Milken's annual conference for investment professionals that "you should all thank me for your bank stocks doing better."
He wrote in the op-ed:
"I cannot conceive of any of the 11 other secretaries I have known making such a statement. Leave aside the question of whether whatever credit is to be claimed should be claimed on behalf of the president. Since when is the stock price of banks the objective or the standard of success for economic policy? And when, as will inevitably occur, bank stock prices decline, will the secretary accept the blame?"
Summers was Treasury Secretary during the Clinton administration and the Director of the National Economic Council under the Obama administration.