If House Republicans can make it over the first hurdle in their lawsuit challenging the Affordable Care Act, their arguments might pose a serious threat to the healthcare law, some legal experts say.

U.S. District Judge Rosemary Collyer is now considering whether to allow the lawsuit to proceed or dismiss it for lack of standing on the House’s part. Collyer’s questions during oral arguments in the U.S. District Court for the District of Columbia, along with her subsequent requests, have led some to speculate that she will grant the House standing and let the lawsuit move forward.