Senate passage of the Schumer-Rubio immigration bill is looking like far less of a sure thing after Sen. Marco Rubio, R-Fla., and Senate Democrats voted down an amendment yesterday that would have secured the border first before granting illegal immigrants citizenship.

For those paying attention to the immigration debate, the legalization-first-border-security-later structure of the Schumer-Rubio bill has never been in question. Just last Sunday, Rubio told Univision, “Let’s be clear. Nobody is talking about preventing the legalization. The legalization is going to happen. … First comes the legalization. Then come the measures to secure the border.”