Which Republicans will sign extremist pledge against marriage equality?

The National Organization for Marriage is doing what it might think is God's work, calling on the Republican presidential candidates to sign its anti-marriage-equality pledge:

"Republicans need to not just give lip service to marriage," Brian Brown, president of the organization, told CNN in an interview. "By signing the pledge they are committing to concrete steps to protect marriage."

Among other things, an advance copy of the five-point pledge provided to CNN calls on candidates to support a constitutional amendment.

If God's at work here, though, it may be in getting NOM to tie the Republicans to a detailed, concrete, and broadly unpopular pledge against equality. But while the pledge will be unpopular with general election voters, it could be a near-requirement for candidates seeking to win over evangelical Republican primary voters, and this is a big week for that effort: 12 actual and potential presidential candidates will be flocking to the Faith & Freedom Coalition Policy Conference, where they'll have the chance to explain how they'd deal with outrages like the Supreme Court possibly ruling for marriage equality and Pope Francis calling for action on climate change.

So, who's going to sign that NOM pledge? Jeb!? Scotty? Marco?