Is this just an example of the polling outfits looking to finally poll accurately before the big contests?
I seem to recall nothing but polls saying Biden all the way.
There is a difference between national polling, and polling for a specific state (Iowa, NH, etc.). You were reading the national polls about Biden. He still leads nationally, but the first two venues, he trails and Bernie is first. Look for super Tuesday coming March 3rd when Alabama, Arkansas, California, Colorado, Maine, Massachusetts, Minnesota, North Carolina, Oklahoma, Tennessee, Texas, Utah, Vermont, and Virginia will hold their presidential primaries on that date. Remember, Bloomberg will be on those ballots.