I don't think it's hypocritical, unless they suddenly change from wanting to ban dark money. I don't think continuing to engage in an act, while calling for it to end, necessarily makes you a hypocrite. It's very much like the F1 comparison someone made earlier. You can call for changes to regulations, while still adhering to the rule of the law. In fact, one of the ways to get loopholes closes quickly in F1 is to abuse the living hell out of the loophole to your advantage. There's no reason to cede an advantage to an opponent, when the regulating body is slow to close the avenue to that advantage. Go ahead and exploit it yourself, and hope that your domination via that method hastens a change of the rule.
At present, it seems that one party is more willing to ban dark money from campaigns, and it just so happens to be the party that's exploiting it the most. That they're willing to cede a funding advantage that they have probably shows more that they actually believe that a ban is the right thing to do. Otherwise, they could just fight to maintain the status quo, and continue to outraise Republicans.