In the United States, political commentators often refer to the "red states", which traditionally vote for Republican candidates in presidential elections, and "<answer>blue states</answer>", which vote for the Democratic candidate. This convention is relatively recent: before the 2000 presidential election, media outlets assigned red and blue to both parties, sometimes alternating the allocation for each election. Fixed usage was established during the 39-day recount following the 2000 election, when the media began to discuss the contest in terms of "red states" versus "<answer>blue states</answer>".
In the United States states that vote for Democratic presidential candidates are known as what?
blue states