While some dismiss the battle between Hillary Clinton and Sen. Bernie Sanders as history, others say it could have a continuing impact on Democratic politics.
Hillary Clinton has taken off the "straitjacket" she says she was forced into during the 2016 Democratic primary.
In her new campaign memoir, the former presidential candidate wasn't exactly subtle about her disapproval of Sen. Bernie Sanders' campaign against her for the Democratic presidential nomination, writing that Sanders, a Vermont independent, caused her "lasting damage," deepened divisions among progressives, and "pav[ed] the way for then candidate Donald Trump's 'Crooked Hillary' campaign."
While many, including Sanders, dismissed Clinton's criticism as an irritating re-hashing of a now-irrelevant battle, the divisions between Clinton's centrist wing of the Democratic Party and Sanders' more progressive (or more populist) supporters could have implications for Democrats in the 2018 midterms and even the 2020 presidential election.
The day after Clinton released her book, Sanders unveiled his much-anticipated single-payer healthcare plan. Short on details and ambitious in its vision, the proposal won the endorsement of 15 top Democrats, many of them likely 2020 presidential candidates.
But other party leaders, including Senate Minority Leader Chuck Schumer and House Minority Leader Nancy Pelosi, distanced themselves from the plan.
"We want to move the issue forward," Schumer said, adding that "there are are many different bills out there," including "many good ones" that he and other Democrats are examining.
Pelosi warned that support for a single-payer system shouldn't become a "litmus test" for Democrats.
In an interview on the liberal podcast "Pod Save America," Clinton said that while she supports the proposal as a "political statement," she doubts it's much more than a pipe dream at this point.
She also criticized the plan's lack of particulars in an interview with Vox.
"I don't know what the particulars are," Clinton told Vox. "As you might remember, during the campaign he introduced a single-payer bill every year he was in Congress — and when somebody finally read it, he couldn't explain it and couldn't really tell people how much it was going to cost."
Democratic strategist Rodell Mollineau, a co-founder of the consulting firm Rokk Solutions, echoed this skepticism.
"I believe in single-payer," he said. "I think there's a big difference between saying you support single-payer and figuring out a way to get the votes and an economic plan in order to get it passed and to pay for it."
Clinton raised the issue of ideological "purity" in her book, arguing that Sanders unfairly narrowed the progressive platform.
"It was beyond frustrating that Bernie acted as if he had a monopoly on political purity and that he had set himself up as the sole arbiter of what it meant to be progressive," she wrote, adding that Sanders simultaneously gave "short shrift to important issues such as immigration, reproductive rights, racial justice, and gun safety."
Mollineau warns that ideological tests could prove just as dangerous for more centrist candidates in 2020.
"When I hear or read that there's some folks who think that someone like a Kamala Harris might not be progressive enough to be our nominee in 2020 — now regardless of whether you support her or not, that's a ludicrous statement and it's a horrible way of applying a purity test," he said.
Steve Schale, a Florida-based Democratic strategist and former adviser to President Barack Obama in the state, says that ideological debates among progressives are not what the party needs right now.
"We're not going to win elections trying to make sure that we have 100% loyalty among 35 or 40% of the electorate, which is what Democrats are," Schale said. "We've got to have a conversation about how we grow the appeal."
Unity among liberals is important, Schale argues, but not nearly as critical as opening the party back up to those independents or one-time Democratic voters who, for a myriad of reasons, abandoned Clinton.
"It's easy to scapegoat the base, or to scapegoat Sanders voters," he said. "But the reality is that [Clinton] lost because the places Barack Obama was much more competitive in in 2008 and 2012 ... she just got torched in."
Throughout Clinton's book "What Happened," and in interviews over the last several days, Clinton argued that Sanders is not a Democrat. She alleged that he ran for the nomination not to help the party, but to "disrupt" it.
And by that measure, she says, he succeeded.
Mollineau argues that Sanders and others eager to challenge the party establishment "can't have it both ways."
"If you want to affect change within the Democratic Party than you need to become closer to the Democratic Party – you can't lob bombs from outside," Mollineau said, adding that while Sanders "could have been doing more to change the Democratic Party from within" throughout his years in Congress, "he just chose not to."
But while Clinton's career in public office is likely over, Sanders still remains a powerful force in national politics. For several months, he's held the mantle as the most popular politician in the country.
Many Democrats, including Jill Filipovic, an author and liberal commentator, argue that it is now Sanders' responsibility to unite the left.
"Sanders has positioned himself as a leader for the future of the left, and his followers agree, with near-messianic worship," Fillipovic wrote in a CNN column. "Embracing the whole left would be a good place for him to start."
But as Thomas Edsall pointed out in a recent New York Times column, there is evidence that progressives have only moved farther left since the election. He cites Pew Research Center data that shows that Democratic voters — particularly whites, Millennials, and post-grads — are much more eager to label themselves "liberal" in 2017 than they were in past years.
And while the left has seen a resurgence in support since November, the money and energy that's flowing into the party is going to Sanders' Our Revolution organization and the Democratic Congressional Campaign Committee, rather than the Democratic National Committee, which is suffering somewhat of a crisis of credibility post-2016.
While Mollineau admits that there are "ideological battles" that will likely be fought in the coming months and years, the tension between Clinton and Sanders won't necessarily remain central.
Although he doesn't put it past campaigns or super PACs to use lingering 2016 tension to "gain a tactical advantage" by aligning a candidate with Clinton or Sanders in an effort to alienate the others' supporters.
"It wouldn't surprise me, it's just a matter of how powerful that is and whether or not voters have moved on by then," he said.