A little-noticed health care provision slipped into a giant spending law last year has tangled up the Obama administration, sent tremors through health insurance markets and rattled confidence in the durability of President Obama’s signature health law.

The attack stems from two years of effort by Senator Marco Rubio and others in Congress to undermine a key financing mechanism in the law. So for all the Republican talk about dismantling the Affordable Care Act, one Republican presidential hopeful has actually done something toward achieving that goal.

Mr. Rubio’s efforts against the so-called risk corridor provision of the health law have hardly risen to the forefront of the race for the Republican presidential nomination, but his plan limiting how much the government can spend to protect insurance companies against financial losses has shown the effectiveness of quiet legislative sabotage.

https://www.nytimes.com/2015/12/10/us/politics/marco-rubio-obamacare-affordable-care-act.html