Story highlights Mark Salter tweeted, "I'm with her" after Trump cited a National Enquirer story to slam Ted Cruz's father

Tuesday's tweet isn't the first time Salter has expressed a preference for Clinton over Trump

(CNN) Hillary Clinton has an unexpected ally: a former top adviser to John McCain.

Mark Salter, a confidant of the 2008 Republican presidential nominee, tweeted Tuesday "the GOP is going to nominate for President a guy who reads the National Enquirer and thinks it's on the level. I'm with her."

the GOP is going to nominate for President a guy who reads the National Enquirer and thinks it's on the level. I'm with her. — Mark Salter (@MarkSalter55) May 3, 2016

Salter was referring to a report Trump cited Tuesday morning from the tabloid, which alleged that it had identified Rafael Cruz, Ted Cruz's father, in a photo with Lee Harvey Oswald months prior to the JFK assassination. CNN has not independently confirmed that report. "I'm with her" is a common phrase Clinton's supporters have used in their social media posts to show their endorsement.

Tuesday's tweet isn't the first time Salter has expressed a preference for Clinton over Trump. In a February Real Clear Politics column , Salter lashed at Trump, writing, "he's trying to make us the worst we can be to satisfy his own vainglory."

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