The Democratic Party used a caucus system to determine the proportion of delegates awarded to Democratic candidates . The caucuses took place May 5 ; as the only Democratic candidate , President Obama won all 183 pledged delegates in the caucus . They , along with the other 20 unpledged delegates , voted for Obama at the 2012 Democratic National Convention in Charlotte , North Carolina
2012 Democratic National Convention
2012 Democratic National Convention
2012 United States presidential election in Michigan