If William's dead (couldn't have happened to someone more deserving IMO), then whoever the opposition is, they're up shit creek without a paddle. James will not be as lenient as he was first time around. Some will try to make stands and fight, but ultimately, while many rallied to William OTL that's FAR from certain here where it seems you're going for a ECW 2.0. Heads will roll (I vote for Devonshire to be the sacrificial lamb), any opposition will be discredited for at least five years (if not longer). James will not have absolute rule, but the stench from this will be enough to give the king the whip hand over parliament.
Unlike what
@Workable Goblin says, Parliament only cemented its whip hand with the Glorious Revolution. Not before. Sure, there were things the king didn't have control of and needed to call parliament for, but it was nothing like as cucked the crown became with the Bill of Rights.
Before anyone points out that there's always Anne, she was a decidedly late convert to William's cause (as in only days before her dad fled). Fact is, if James stays on the throne, keeps England out of the 9YW (unlike William, he had no reason to get involved) and doesn't lean too pro-French (again, he only threw his lot in with the French once William invaded with Habsburg backig), he should be able to ride out the storm. In fact, one of the big reasons W3 was even able to get the English to side with him was he played on the large number of Huguenots (who had only been welcomed into England at James' insistence) fleeing Louis XIV's dragonnades to panic the English into thinking James would do the same. So, provided James remains even-handed in matters like religion - no dragonnades or forced conversions - I don't see why he'd be deposed. In fact, assuming England thrives (while the rest of Europe is tearing itself apart in the 9YW), James might even remembered better than as "Jimmy the Beshitten".
@VVD0D95