Marco Rubio (AP) Sen. Marco Rubio (J. Scott Applewhite/Associated Press)

The voices of the opponents of the Gang of Eight immigration bill are growing louder, but I would still bet in favor of Senate passage of the bill. Thirty days ago, it seemed possible that the bill backed by Sen. Marco Rubio, R-Fla., would get 70 or more votes, but today you have to guess the vote total will be closer to 60.

The latest obstacle for the immigration reform measure is the bewildering fact that the bill requires the Department of Homeland Security to “submit plans” that outline how border security will be achieved, and then asks Homeland Security to self-assess whether the border has been secured after five years as a result of those plans. Who among us trusts the government to self-critique anything these days? It seems unlikely that Homeland Security would admit its own failures, and Republicans have already highlighted that the Obama administration continually exaggerates the current state of our border security.

As I always say, in Washington a bumper sticker beats an essay. Well, “border security first!” is a pretty compelling bumper sticker, while the explanation of how the border security triggers and eventual government self-review would actually work is a cumbersome essay at best.

At town hall meetings back home, GOP members of Congress will face tough questions from their constituents about the border security measures in this bill. The memory of the failure of the 1986 immigration reform bill, when promises to secure our border were left unfulfilled, is understandably making Republicans skeptical that it will be any different this time around.

The entire Senate process has become unflattering, as most Republicans will oppose the bill as it currently stands, and it has no chance to pass in the House with a majority of Republicans. If the bill passes the Senate, it is not necessarily good for Republicans with Hispanic voters. It might keep things from getting worse for Republicans for a while. But if the bill fails, the pounding the GOP will take from the media and others on the left will harden Hispanic opposition to Republicans and confirm many of their worst suspicions.

Politically, Republicans are now in a no-win situation. We can only limit our losses and hope for opportunities to impress Hispanic voters — probably on economic issues — at some later date. As former Mississippi governor Haley Barbour said yesterday at the Bipartisan Policy Center’s discussion on immigration reform alongside former Florida governor Jeb Bush, “If it doesn’t pass, the news media’s already decided it’s the Republicans’ fault.”  Republicans in the Senate who support the bill are now mostly in damage-control mode as they try to get to 60 votes. The opportunity to do some real good for the GOP on the immigration issue has been squandered.