The board reviewing his case has overturned Facebook’s content takedowns in almost every decision so far. But the ex-president poses special challenges.Former President Donald Trump spent years butting heads with Facebook over its standards, including posts before and after the election that the company either adorned with warning labels or took down entirely for making unfounded claims. | Alex Wong/Getty ImagesIf former President Donald Trump manages to get back on Facebook and Instagram this month, his win will rest on a series of close calls.Facebook’s oversight board is expected to rule...…The board reviewing his case has overturned Facebook’s content takedowns in almost every decision so far. But the ex-president poses special challenges.Former President Donald Trump spent years butting heads with Facebook over its standards, including posts before and after the election that the company either adorned with warning labels or took down entirely for making unfounded claims. | Alex Wong/Getty ImagesIf former President Donald Trump manages to get back on Facebook and Instagram this month, his win will rest on a series of close calls.Facebook’s oversight board is expected to rule...WW…