Will U.S. Sen. Marco Rubio, R-Fla., ever stop atoning for his apostasy in having supported an overhaul of America's broken immigration system? Or is he so politically pliable and ideologically biddable that he will take any stance to shield himself from the ugly nativism Donald Trump has tapped among Republican primary voters?

It was only in the spring that Rubio, speaking in Spanish to Univision, deemed "important" President Obama's program to allow young people who entered the country illegally before age 16 to apply for work permits. Now, speaking in English in New Hampshire, Rubio says the program should be ended unless broad immigration reform is enacted — the sort of broad reform he advocated in 2013 and later rejected in the face of right-wing outrage.

Let's be clear:  By canceling the program, Deferred Action for Childhood Arrivals (DACA), Rubio would expose to deportation proceedings the 700,000 young people, known as Dreamers, who have grown up and attended school and even college in the U.S.

Rubio's craven flip-flop has been especially stark given the prominent role he played as a member of the Gang of Eight bipartisan senators who wrote the 2013 immigration reform bill that passed the Senate but went nowhere in the House.

As the GOP presidential nominee in 2012, Mitt Romney said he would not deport young people covered by DACA. Yet under Trump's malign influence, similarly moderate stances on immigration are now regarded as political self-destruction.

From an editorial in the Washington Post