This week's edition of The 45th newsletter.

The past week has been marked by heightened Republican criticism of the sitting Republican president, with outgoing senators and former presidents issuing thinly veiled (and not so thinly veiled) rebukes of Donald Trump.

Speaking at a conference he convened in New York last week to support democracy, Trump's GOP predecessor George W. Bush said: "Bullying and prejudice in our public life sets a national tone, provides permission for cruelty and bigotry, and compromises the moral education of children... We’ve seen nationalism distorted into nativism, forgotten the dynamism that immigration has always brought to America.”

While the former president was careful not to mention Trump by name in his speech, Arizona Republican Senator Jeff Flake was not so restrained when announcing on Tuesday that he would not seek re-election in 2018. He declared on the US Senate floor that he “will no longer be complicit or silent” in the face of the president’s “reckless, outrageous and undignified” behaviour. He deplored “the personal attacks, the threats against principles, freedoms and institutions, the flagrant disregard for truth and decency” that he said had become prevalent in American politics in the Trump era.

For his part, Trump renewed his attacks on another critic in the Republican Party on Tuesday. He tweeted that Tennessee Senator Bob Corker "couldn't get elected dog catcher in Tennessee". Corker responded that the president is "debasing" the country.

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