As long as Tulsi Gabbard does not cannibalize votes from the one plausible re-aligner candidate to unite around, Bernie Sanders, there's no problem in her running a campaign before the actual primary voting begins. She could help build enthusiasm for realignment during the debating stage, and get most of her supporters to go to the polls for Bernie during the voting stage. She endorsed him last time, and they mostly overlap on the issues, so that should not be too hard for her to do.
The real threat to uniting around Bernie is Pocahontas, who will not campaign on the same issues as he will -- she is a Reaganite, not a realigner -- but who will still position herself as an enemy of the banks. She will not drop out before voting begins, nor eagerly plead with her supporters to vote for Bernie, whom she refused to endorse last time.
With Tulsi in the race during the debate stage, she and Bernie can tag-team the neoliberals -- Bernie focusing more on domestic issues, and Tulsi on foreign policy. They will force the dozen other neolibs to promise crushing austerity programs domestically, and endless wasteful destruction abroad.
That will be the main split among the candidates -- survival or extinction. Most voters will not care what particular flavor their austerity/warmonger candidate comes in. They are sick of the failed Reaganite system, and want major change. That leaves only Bernie/Tulsi. The voters who materially benefit from austerity and war will split their vote a dozen different ways, just like the anti-realigners did during the GOP primary in 2016, clearing the way for a consolidated realignment vote in favor of Trump.
Tulsi's function in the prelude to voting will be to force voters to choose between identity politics and material issues like healthcare, wages, and war. She will be pilloried by liberals for not being pro-gay, pro-choice, or pro-Islamist. These are empty dead-end identity issues for materially comfortable liberals to jerk themselves off to -- no different than being vocally against gay marriage, pro-life, or anti-Islamist are empty identity issues for materially comfortable conservatives.
Someone who wants to improve material conditions first and foremost will form an alliance with anyone else who does, regardless of their differences on less important social-cultural issues. So Tulsi is perfectly happy to endorse and work with Bernie, who holds more liberal positions on the social issues. And Bernie is happy to work with Tulsi. Each one of them does not care about these marginal identity issues, or else their alliance would never have formed.
Those who put empty identity issues first could stand behind Bernie but would reject Tulsi. This includes most of the so-called "socialists" who have re-branded themselves after Bernie's 2016 campaign. They're not the inheritors of historical socialism, which is class-first and anti-imperialist. They just got tired of being called SJWs, but still could not leave behind their favorite label of "social justice". In practice, in the US in 2019, "socialism" mainly means "social justice-ism" AKA "intersectionality".
That's how the DSA shot up in membership by several orders of magnitude overnight -- tens of thousands of former liberals or progressives did not suddenly adopt a whole new worldview, vision, strategy, tone, or set of goals. They're the same ol' libs and progs from before Bernie showed up, but since the hot new phenomenon labeled himself a "democratic socialist," well, they had to adopt that label as well. They've always styled themselves as radicals, and "socialism" has a radical connotation, so they're happy to adopt the term. But fundamentally, they are stylistically-radical liberals ("radlibs" in the words of the class-first, anti-imperialist Left).
These libs and progs will not condemn Tulsi for her economic policies, which they mostly share, so these opponents are not pro-austerity. They are pro-welfare state. But they will scold her for discussing radical Islamic terrorism, on the basis of any criticism of any Muslim individual or group being Islamophobic. She will make these crazy woketards say that we must let ourselves get blown up by jihadists just to prove that we aren't Islamophobic. And that anyone who isn't a Sunni Muslim in the Middle East must let themselves get blown up, their shrines desecrated, and their villages bulldozed, to prove they have not bought into the Western white supremacist myth of radical Islam.
These identitarian attacks against Tulsi's foreign policy agenda benefit the Pentagon's alliance with the Salafi jihadists of the Gulf like Saudi Arabia, who along with Israel are our partners in imperialism throughout the Middle East. This puts the woke crowd in league with the imperialists. And if there's anything the American people hate, it's political correctness and endless wars -- combine them both, and it's an electoral death wish. Tulsi's campaign will serve to flush the woke imperialists out of any realignment coalition.
There are far more politically incorrect anti-imperialists than there are woke imperialists, and being more Independent in partisan affiliation, they would have no problem invading the Democrat primary to vote for Bernie, if Tulsi withdraws and endorses him. The woketards are far more moralistically partisan, and would rather drop out of Bernie's electoral coalition if it meant sharing space with those who are ritually unclean ("deplorable"). All the more space for us, then, who don't mind mingling with different groups, as long as they share our goals.
Realignment of the Democrats into the dominant party, after Reaganism, requires purging themselves of their anti-coalitional members, i.e. those who want a smaller purer party. All politics is coalitional, and a dominant party must be even more of a cohesive coalition than the opposition party. And in order to realign, they must secure permanent massive defections from the current dominant party. In 2019, that means stealing away legions of Trump voters for the indefinite future. The only way to do that is to say "We're going to bury the hatchet on all this pointless culture war BS, and focus on improving material living standards at home, and cutting loose our dead weight empire abroad."
Woketards will never bury the hatchet on the culture wars, so they will purge themselves out of this new realignment coalition, especially once they get a taste of large numbers of former Trump voters sharing the room with them. Tulsi's campaign can be a call to the Trumpian cavalry to come to the aid of Bernie during the primary, when he's most desperate.
The strategy for Trumpian populists should be supporting Tulsi during the debating stage, then voting for Bernie when the polls open. Bernie is the only viable candidate to crush the identity politics crowd for good, by winning on material issues after getting vilified as a racist sexist old white man. Just as Trump was the only viable candidate to crush right-wing identity politics (pandering to evangelicals), by winning on material issues after getting vilified as an atheist adulterer with "New York values".