A liberal refrain is to "be on the right side of history." The phrase relieves dissonance on controversial topics. When challenged on gay rights, for example, they might say, "You have some good points, but my position on this issue is on the right side of history." It's hard to imagine a conservative saying such, perhaps because they are vaguely nostalgic for the past and its values and traditions.
Being on the right side of history is about future-proofing one's morality. You are predicting that your position will increase in popularity or validity over time. We are ultimately always grounded in the mores of the present, a present that is always changing. Why not expand one's definition of morality to include the surface area underneath the value of your position over the rest of your lifetime?
At the very least, futurism should be a sanity check on morality. Take some moral conclusion, then imagine if people would find that conclusion abhorrent 50 years from now. If so, maybe you should reconsider your position.
I am more likely to be in moral disagreement with an American from 200 years ago than I am with an American today. Back then, the average American cheered on Manifest Destiny, owned or knew people who owned slaves, and tolerated duels as a way of resolving conflict.
The counterargument to futurist morality is that there are temporary regressions, such as Mao's cultural revolution or Nazism. History eventually corrected itself, so it seems, but we are just being selective with time windows.