car suddenly pulls to side on 2002 Mercury Villager

When driving the mercury villager suddenly pulls to the side then corrects after new front tires and new alignment.

Asked by for the 2002 Mercury Villager
switch tire left to right see if it still pulls
2 more answers
So the problem is no more? Or, is it still doing this? If so, there are a few possibilities like a failing brake pad, bad wheel bearing, or, the alignment was shunted by hitting a curb/bump/rr track/etc....
Check Tie Rod.
It could be loose popping in and out of place.