Even as the Sunday shows were alive with predictions that a deal is close on immigration reform, Marco Rubio took the occasion to cast doubt on the prospects for success by joining other Senators who are calling for the process to slow down:

“We will need a healthy public debate that includes committee hearings and the opportunity for other senators to improve our legislation with their own amendments,” he said on Sunday. “Excessive haste in the pursuit of a lasting solution is perhaps even more dangerous to the goals many of us share,” he said on Saturday.

As my Post colleague Evan Soltas points out, Rubio has effectively built himself a “very clear escape hatch” on immigration. If he needs to bail, he’s got his excuse: The process was rushed, or Democrats were unfair procedurally to Republicans.

By my count this is the third such escape hatch Rubio has created for himself. The first came when word leaked that the White House had drawn up its own plan that was marginally different from what pro-reform Republicans want. Rubio said this had threatened the prospects for success, even though his plan was very similar to the President’s. But then John McCain and Lindsey Graham publicly proclaimed their belief in Obama’s sincere desire to make the process work. The second came back when Rubio claimed that unions were putting reform in peril because of their dispute with business groups over the guest worker program. But now that dispute has mostly been resolved.

Now, escape hatch number three is to join the “slow down” caucus. Only in so doing, Rubio is joining with other Senators who are urging a go-slow approach, such as Ted Cruz and Jeff Sessions, who may be urging a slowdown so the armies of the right have time to mobilize and strike fear into any reform-minded Republican officials, killing reform.

Indeed, one group opposed to reform has explicitly called on Senators to slow the process down, apparently for the purposes of derailing it. And we’ve seen this before: back in 2007, opponents of reform similarly tried to slow the process, with Senator John Cornyn urging colleagues to “slow down and read this bill” because Americans had not yet digested the plan. Now, six years later, we’re again hearing the calls to “slow down.” But the American people have made their verdict clear: They want a path to citizenship.

No doubt Rubio has a very tough balancing act to strike. He needs to reassure conservatives that he’s prepared to walk away from any deal, and that he’s getting them everything he can in the process. If he does this successfully, it could potentially bring some of them along. But as Benjy Sarlin points out, Senate Democrats have already vowed not to procedurally rush the process and have promised to run things through the typical committee and amendment process. Lending aid and comfort to the “slow down” caucus could make things worse, given that their apparent aim is to allow opponents more time to kill reform.