Republicans in Congress are giving President Trump the cold shoulder as he pushes them into another risky political battle to replace Obamacare, insisting they won’t act until the White House delivers a detailed proposal.

The Trump administration is pursuing a federal lawsuit that could invalidate the Affordable Care Act signed by former President Barack Obama nine years ago, removing popular coverage protections for Americans with pre-existing medical conditions. Fearing a voter backlash, Republicans who for years championed repealing the law are balking at the president’s latest attempt to fulfill a 2016 campaign promise, believing the window for success has closed.