During the 2012 presidential race, the Mitt Romney campaign ran an ad quoting Barack Obama as allegedly saying (in his 2008 race against John McCain), "If we keep talking about the economy, we're going to lose."
But, this was Obama's complete statement: "Senator McCain's campaign actually said, and I quote, If we keep talking about the economy, we're going to lose."
In the current 2020 presidential race, the Trump campaign has run an ad quoting Joe Biden as allegedly saying, "You won't be safe in Joe Biden's America." But, this was Biden's complete statement: "Trump and Pence are running on this, 'you won't be safe in Joe Biden's America' and I find it fascinating. And what's their proof? The violence we're seeing in Donald Trump's America!"