Democratic presidential candidate Sen. Bernie Sanders has long chosen to self-describe on the ballot and in Congress as an Independent. In spite of that, he has always caucused with the Democrats in the House and Senate, and has always endorsed the Democratic nominees for President. In exchange for this, the Democratic Party of Vermont has agreed since 1990 to not back any Democratic challengers to Sanders, even in years when a nominal Democratic candidate was on the ballot. In some years, Sanders has won the VT Democratic primary as a write-in, but declined to accept, leaving the party without a formal nominee in those elections.
Sanders’ idiosyncratic self-description of his partisan affiliation has caused some speculation that he would be denied ballot access for the Democratic primary in some states on the basis of not being a Democrat. In New Hampshire in particular, candidates must affirm that they are a “registered member” of the party, but Sanders, like roughly half of Americans, lives in a state that doesn’t have partisan voter registration.
Unsurprisingly, New Hampshire’s Ballot Law Commission has unanimously ruled that Sanders is a Democrat “on the preponderance of the evidence,” and can therefore appear on the Democratic primary ballot. Among the reasons cited, is that both the DNC and NH-Dems have firmly backed Sanders as a bona fide Democratic candidate, and in his FEC Declaration of Candidacy he listed his affiliation as “Democratic.”
However, Sanders continues to self-identify as an Independent, including on the official Senate registry, and in deference to this most media outlets still grant him the designation “Sen. Sanders (I-VT)” instead of “Sen. Sanders (D-VT)”