A caveat is that the poll does not necessarily ask whom respondents will vote for. Voters can of course respect a candidate but for various reasons choose another, perhaps because of a specific policy proposal.
Nonetheless, it seems the question is not if, but how, Mahfud will run. From the polls alone, a Kalla-Mahfud pair sounds unbeatable. Mahfud, as Javanese (Kalla is from Sulawesi) might even make more sense at the head of the ticket. But all we have thus far is speculation. My guess is that Mahfud will have a more difficult time passing the first round of the presidential voting than the second. In other words, he'd need enough name recognition and a political party apparatus to support his bid and make it past the first round.
Mahfud's response to all the speculation has certainly not been Shermanesque. According to The Jakarta Post, his response to the speculation was:
I can’t decide now because it will affect my present position as chief justice with the Constitutional Court, as well as at my [academic] institution. Let’s wait until after my term expires in April.Which sounds like a good reason for retiring from the MK!