But so far, public pollsters — typically run by news outlets and colleges — have not changed much about their approach. Few if any of the public pollsters that conducted surveys ahead of Tuesday’s elections for governor in Virginia and New Jersey appear to have adopted significant methodological changes intended to better represent the rural, less-educated white voters who pollsters believe were underrepresented in pre-election surveys.

On the other hand, private pollsters — typically employed by campaigns and parties — have already begun to make changes. This is especially true among Democrats stunned by Donald J. Trump’s upset victory, but Republicans are making changes as well. The adjustments are already playing out in Virginia, where pollsters will have one of their first chances to put postelection shifts to the test.