With Congress preparing to vote on the Iran nuclear deal later this month, the proverbial fat lady in the wings is preparing for her solo.

After months of lobbying, millions spent on advertising, hundreds of op-eds, thousands of articles and an incalculable number of tweets, the opponents of the P5+1 nuclear agreement with Iran are on the verge of a major defeat. Indeed, the White House is now pushing for Democrats to filibuster the vote in the Senate and prevent President Barack Obama from having to veto any resolution. Even if not blocked in the Senate, the White House has enough votes in the House and is only a handful short in the Senate of sustaining a veto. ...