EXPLAINER: Why do the media call races in US elections?

Each with different rules and regulations, and no national elections commission to tell the world who wins. The Electoral College actually chooses the president under the U.S. Constitution, acting in a process that starts with the popular vote across the republic. In that strange vacuum created by a federalist system and worsened — in the 1800s — by the slow counting and communicating of returns, news organizations emerged as major players in first, collecting and adding together the vote from each state's election officials around the country, then announcing the victor based on that vote count.