~25% of House Dems crossed the aisle to vote on a Republican amendment to the ACA to ban federal funding of abortion[1]. While that specific amendment failed in the Senate, it still forced a handshake deal that Obama would issue an EO to that effect.

It seems very unlikely that the ACA could have been passed if it enshrined abortion rights.

[1] https://en.wikipedia.org/wiki/Stupak%E2%80%93Pitts_Amendment