Story highlights Some will vote for the Democrat, while others will vote for the Libertarian or write someone in

The letter makes no mention of Hillary Clinton

Washington (CNN) More than two dozen former Republican members of Congress released a letter Thursday saying they cannot vote for Donald Trump because he "makes a mockery" of their principles.

Though the letter makes no mention of Hillary Clinton, organizer Andrew Weinstein said some of the members will vote for the Democrat, while others will vote for Libertarian Gary Johnson or write in a candidate.

"Given the enormous power of the office, every candidate for president must be judged rigorously in assessing whether he or she has the competence, intelligence, knowledge, understanding, empathy, judgment, and temperament necessary to keep America on a safe and steady course," the lawmakers wrote. "Donald Trump fails on each of those measures, and he has proven himself manifestly unqualified to be president."

The letter was circulated by former Oklahoma Rep. Mickey Edwards and former Missouri Rep. Tom Coleman.

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