It was in the early hours of Saturday morning that Prime Minister Shinzo Abe's ruling bloc rammed through the Diet a contentious immigration bill, at last defeating hours of fierce protest by opposition lawmakers who had shouted at — and even wrestled with — a committee chairman trying to finalize the vote.

But Abe's success in enacting the landmark bill, which will bring a legion of foreign workers into a nation traditionally averse to immigration but in desperate need of laborers, may turn out to have been a pyrrhic victory.

As this year's extraordinary Diet session wrapped up Monday, Abe found himself not an inch closer to fulfilling his longtime ambition of amending the nation's postwar Constitution. The heavy-handed way the ruling bloc tried to pass the revised immigration law has taken a toll, antagonizing opposition lawmakers so much that they have refused to sit down and reboot constitutional debate with pro-revision forces.