( CNN) Donald Trump won the presidency in 2016 with the electoral college. But in three states( Michigan, Pennsylvania, and Wisconsin ), his margin over opponent Hillary Clinton was less than 50,000 votes each. In fact, just 77,744 total votes in those three states separated the two candidates. If Clinton had won all three, she would've been victorious over Trump. But she wasn't. Every vote mattered in the 2016 election.