I too agree it is the last chance for unions. Unions were already dangling by a thin thread and with the election of Trump, that thread is about to snap.
Unions in the Trump era face a familiar dilemma: how to grapple with powerful politicians poised to launch broad attacks on the American working class. The stakes of the dilemma are no less than those faced by PATCO under Reagan: unions that give their imprimatur to an anti-union president will soon find that president destroying them and the rest of the labor movement anyway.
Much has been made of unions’ lack of a unified approach to the Trump administration, varying from hostile to cautious to sycophantic. Despite their weak position after decades of retreat, the choices made by labor leaders still matter. Unions must present a unified resistance with one another, as well as with nonunion workers, against the Trump administration. Union support for Trump will provide Trump the populist veneer needed to launch and sustain hideous attacks against not only unions, but civil rights, immigrants, and black, Latino, and Muslim-Americans.
Trump is poised to launch a multi-faceted attack on all working Americans. Trump may offer a program that benefits certain unions in the very short term — such as the building trades through infrastructure spending — but his assault on public education, financial regulation, and immigrant rights (just to name a few) would be devastating for working people as a whole.

Besides his attacks on workers in general, Trump will also attempt to directly legislate American unions out of existence. He has already expressed ardent support for Right to Work legislation (Vice President Pence previously ushered its passage in Indiana as governor), and Republicans have already introduced a national right-to-work bill into Congress. If passed, national Right to Work spells, at best, a defensive struggle for survival for most unions.