He doesn't have to win just make it an issue at the right stage of the campaign.
Wow on the lawsuit. But where does it say that Trump said Ted Cruz should leave the presidential race?
Rep. Alan Grayson of Florida, an attorney and Democratic Senate candidate, tells U.S. News he will file a lawsuit challenging Cruz’s eligibility should he overtake Trump and win the nomination — a scenario that’s at least plausible with the senator besting Trump in some Iowa polls.
Which is why its good tactics to get this all out now and make it very old news by that time...