It's going to be a battle.
The reason so many horses fall short at the Belmont after fantastic runs through the first two races of the Triple Crown is the combination of the extra distance and the exhaustion carried over from the previous two races. Justify's runs at the Kentucky Derby and Preakness Stakes both were ramped up a few degrees of difficulty thanks to sloppy conditions, and likely took even more out of him than they would have through a more temperate year.
With Justify running out of the post, he might be forced to jump to the lead and match an early pace — the speed of which could determine whether or not he has anything left in the homestretch.
It's not difficult for me to imagine Justify losing his dominant cruising speed for the final lengths of the race and getting caught at the wire.
That said, if any horse can overcome two muddy tracks and a third field stacked with talent some of whom are running on fresh legs, it's Justify. He's massive, and racing fans have hardly seen him break a sweat through the first two legs of the Triple Crown. He's never lost a race in his life, and watching him run just once makes it apparent why.
I'm not sure if I'll be betting on Justify to win yet, but I know I'll be rooting for him.