Once Friday’s immigration “breakthrough” took root in the Senate, final passage of the amended ‘Gang of Eight’ legislation became a fait accompli. Barring a seismic political disruption, Harry Reid will file for cloture on the Hoeven-Corker substitute amendment later today, clearing the way for final passage by week’s end. It’s the allure of a fairly speedy approval process that likely explains why prominent ‘gang’ members were happy to abandon their pretextual grievances against the Cornyn amendment and throw their arms around the new plan. Byron York’s Senate sources are telling him that this ballgame is over: