Vermont Senator Bernie Sanders wrote a stinging letter to the Center for American Progress, the presumptive think tank of the Democratic Party establishment. (Sorry, no link available to me, but the story appeared today in the New York Times.)

”Senator Bernie Sanders, in a rare and forceful rebuke by a presidential candidate of an influential party ally, has accused a liberal think tank of undermining Democrats’ chances of taking back the White House in 2020 by “using its resources to smear” him and other contenders pushing progressive policies.

“Mr. Sanders’s criticism of the Center for American Progress, delivered on Saturday in a letter obtained by The New York Times, reflects a simmering ideological battle within the Democratic Party and threatens to reopen wounds from the 2016 primary between him and Hillary Clinton’s allies. The letter airs criticisms shared among his supporters: That the think tank, which has close ties to Mrs. Clinton and the Democratic Party establishment, is beholden to corporate donors and has worked to quash a leftward shift in the party led partly by Mr. Sanders.

“This counterproductive negative campaigning needs to stop,” Mr. Sanders wrote to the boards of the Center for American Progress and its sister group, the Center for American Progress Action Fund. “The Democratic primary must be a campaign of ideas, not of bad-faith smears. Please help play a constructive role in the effort to defeat Donald Trump.”

“Mr. Sanders sent the letter days after a website run by the action fund, ThinkProgress, suggested that his attacks on income inequality were hypocritical in light of his growing personal wealth. The letter is tantamount to a warning shot to the Democratic establishment that Mr. Sanders — who continues to criticize party insiders on the campaign trail — will not countenance a repeat of the 2016 primary, when he and his supporters believe party leaders and allies worked to deny him the Democratic nomination.”

CAP continues to celebrate and protect the failed education policies of the Obama administration, which were built on the foundation of George W. Bush’s disastrous No Child Left Behind. The Bush and Obama education policies were twins and relied on testing, punishment, choice, and accountability. The Bush-Obama regime is responsible for the closure of hundreds of public schools, mostly in communities of color, and their replacement by privately managed charter schools.

Last year, CAP’s education analyst Ulrich Boser wrote an excellent critique of vouchers. I wrote to congratulate him and asked when he would apply the same critical lens to charter schools, and he replied, “We will have to agree to disagree.”

I interpreted his response to mean, “Never.”

CAP is in the debt of the corporatist, Wall Street Democrats, who won’t break ranks with Obama, Duncan, DFER, or Wall Street. They are the voice of the past.