The morning after taking the podium at the Democratic National Convention in Philadelphia and giving a full-throated endorsement of his political rival Hillary Clinton, Bernie Sanders told reporters that he will return to the Senate as an independent.

“I was elected an independent,” Sanders told reporters at a Bloomberg-hosted breakfast the morning after.

The move is somewhat expected, but the gravity of the decision feels a little off-putting, coming only hours after he tried to unify the Democratic Party, pleading for his own supporters to rally behind presumptive Democratic nominee Clinton.

Bernie Sanders tells @bpolitics breakfast w/reporters he'll return to the Senate as an Independent, not a Dem: 'I was elected as an Ind.' — Susan Page (@SusanPage) July 26, 2016

Sanders, a self-described “Democratic Socialist,” has been officially been an independent politician since 1979, though he has often caucused with Democrats. Last year, he made the move to the Democratic Party in an attempt to win the presidency.

When he submitted his paperwork to run for president last April as a Democrat, he seemed relatively uncommitted, or even conflicted about the designation.

When asked if he was actually a Democrat that day, Sanders told Seven Days, a hometown Vermont paper: “No, I am an independent who is going to be working with the—” and then cut himself off mid sentence.

Later, at a Democratic town hall from earlier this year, he changed it up, responding to the same question: “Of course I am a Democrat and running for the Democratic nomination.”

The question of whether he was ever really a Democrat crept back into the picture this last week, when a trove of emails were leaked from the Democratic National Committee. One of the emails that has received the most scrutiny was one sent by now ousted DNC chair Debbie Wasserman Schultz, about Sanders’ complaints that the DNC was undermining his campaign.

“Spoken like someone who has never been a member of the Democratic Party and has no understanding of what we do,” she wrote. Schultz resigned from her position this week after the perceived bias the emails showed.

The ambiguity of Sanders’ own self-designation has played out through this week, when some viewers were confused that on-screen television graphics were listing him as an independent.

“Like it or not, the system is designed to reward fealty to the party,” wrote James Nevius in the Guardian this week, on how Sanders was treated by the DNC. “Hillary Clinton has been a figure in Democratic politics since her husband’s first term as Arkansas governor in 1978.”

Regardless of his personal political identity, the impact that a short-lived Democratic Sanders left on the party will likely be felt for a long time, as the Democrats’ new party platform shows.

“I think if you read the platform right now, you will understand that the political revolution is alive and kicking,” Warren Gunnels, Sanders’s policy director, told NBC News. In many issues, the party has moved significantly to the left, as has Clinton, in trying to keep up with Sanders’ broad appeal.

The campaign got “at least 80 percent” of what it wanted from the party platform, said Gunnels.