Rank hypocrisy on birtherism

Four years ago, when Donald Trump briefly campaigned for president before quitting the race, he focused on the issue of Barack Obama’s birth certificate, claiming to possess evidence that the president was born abroad and therefore ineligible for his office.

But this year, Trump respects the candidacy of Ted Cruz, and approvingly re-tweeted a suggestion for a Trump-Cruz ticket—despite the fact that Cruz acknowledges he was born in Canada (and thus, by Trump’s standard, ineligible).

Of course, Senator Cruz is eligible to run: because his mother was American, he counts as a “natural born” citizen under the Constitution. Obama’s mother was also born in the U.S., so why would it matter where he was born, or who his father was? Actually, the father of Ted Cruz was also a foreign national at the time of the Senator’s birth.

Is there any explanation for Trump’s continued questions on Obama’s eligibility, while embracing the candidacy of Cruz, other than political convenience?