Washington (CNN) Facing potential impeachment for pressuring Ukraine to help him secure re-election next year, President Donald Trump has pivoted to a new defense, saying his efforts were apolitical and solely motivated by his good-faith desire to root out "corruption."

But Trump's latest defense doesn't hold up under scrutiny. New documents unearthed from the impeachment inquiry, along with many of Trump's past comments, undermine his claim that his efforts to spur a Ukrainian investigation into Democratic frontrunner Joe Biden was "not about politics."

Trump mounted this new "anti-corruption" defense in a series of tweets, campaign commercials and at an impromptu gaggle with reporters Friday morning on the White House lawn, where he repeated the word "corruption" 29 times in 23 minutes.

"Let me tell you, I'm only interested in corruption," Trump said. "I don't care about politics. I don't care about Biden's politics.... I don't care about politics. But I do care about corruption, and this whole thing is about corruption... This is about corruption, and this is not about politics."

Facts First: Even though Trump said, "this doesn't pertain to anything but corruption," the facts tell another story. Trump showed little interest in fighting corruption before Biden launched his campaign, and official government records suggest Trump was motivated by politics.

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