Actually, the newly elected Muslim mayor’s endorsement of Hillary just as readily validates Trump’s run well beyond any gain he thought his statement could yield for her.
Just looked it up: Hillary congratulated Sadiq Khan three days ago for winning the London Mayoralty!
This was a quid pro quo, then. Trump’s got Hillary coming and going on the Muslim issue! Hope he uses it.
(wanted to say tit for tat but that would require eyebleach)