Following his win last night in North Carolina, the Service Employees International Union (SEIU) claimed today that Barack ObamaBarack ObamaGinsburg: Trump Supreme Court nominee Neil Gorsuch is 'very easy to get along with' Ivanka, Kushner pushed to strike climate deal criticism from executive order: report Pence: Democrats' Obamacare promises were 'fake news' MORE is the Democratic Party's presumptive presidential nominee.

SEIU endorsed Obama Feb. 15 and has worked to bolster support for him in the Democratic race. According to SEIU, its members have gone door to door and made phone calls for Obama, and SEIU has aired pro-Obama ads on television (see the union's Indiana ad here). SEIU claims 1.95 million members nationwide.