There are fresh battles lines in the 2020 presidential campaign, reflecting an unpredictable rivalry between two Democratic politicians — one who isn’t even running this cycle and another who is polling at barely 1 percent.

It began when former Democratic presidential nominee Hillary Clinton suggested this week that current primary contender Rep. Tulsi Gabbard of Hawaii is being used by the Russians, who could be plotting a third party run to siphon votes from the eventual Democratic nominee. It’s a scenario that Clinton is sensitive to, since she blames Russian election interference and Green Party candidate Jill Stein for her loss to President Trump.

Gabbard, in a scathing response, called Clinton “the queen of warmongers, embodiment of corruption, and personification of the rot that has sickened the Democratic Party for so long.”

Hillary Clinton said Russian election inference "altered the outcome in enough places," and contrasted President Trump's response to Bush's reaction to 9/11. (The Washington Post)

“It’s now clear that this primary is between you and me,” Gabbard wrote on Twitter. “Don’t cowardly hide behind your proxies. Join the race directly.”

Clinton has not directly responded, but her spokesman, Nick Merrill, told CNN, “If the nesting doll fits.”

Merrill, in an interview Saturday, said Clinton was “not saying Americans are Russian spies but that Russia has found ways to take advantage and is not being held responsible by anyone in government.”

Few outside Clinton’s immediate orbit defended her comments. The closest anyone came was Sen. Cory Booker (D-N.J.), who retweeted Gabbard’s reaction to Clinton with a viral GIF from the June debate when he glanced “side eyed” — a look that often conveys shock or disdain — at another candidate. That garnered a reply from Clinton — a viral GIF of her own from a 2016 debate where she exhales, says, “okay,” smiles and shimmies her shoulders.

Minnesota Sen. Amy Klobuchar, whose Iowa bus tour had been overshadowed by the Gabbard-Clinton fight, told reporters on Friday that Clinton could “defend herself, and will.” Asked about the story again on Saturday, she pivoted to talk about her election integrity legislation.

“This is something I’m not getting into right now,” she said. “I will talk about election security, because I think that’s much more significant than any Twitter fight going on right now.”

But two of the nonpoliticians in the Democratic primary, entrepreneur Andrew Yang and author Marianne Williamson, sided with Gabbard.

Yang tweeted that Gabbard, a veteran, “deserves much more respect and thanks than this.” Williamson accused the Democratic establishment of “smearing women it finds inconvenient.”

“The character assassination of women who don’t toe the party line will backfire. Stay strong @TulsiGabbard. You deserve respect and you have mine,” Williamson tweeted.

Notably, Clinton — who made the comments on a podcast hosted by David Plouffe, a former adviser to President Barack Obama — never used Gabbard’s name. But Gabbard is the only female candidate in the Democratic primary who has been accused of having ties to Russia.

“I’m not making any predictions, but I think they’ve got their eye on somebody who is currently in the Democratic primary and are grooming her to be the third-party candidate,” Clinton said.

Gabbard has repeatedly ruled out running as a third-party candidate. But she has been courted to run in the general election outside the Democratic Party by activists who believe the two-party system is corrupt and should be cast aside.

Stein has suggested in the past that Gabbard “should become a Green” because her comments were “similar to our message.”

In the podcast interview, Clinton also accused Stein, who won more votes in several states than Trump’s margin of victory over Clinton, of being a tool of the Russians.

“Yes, she’s a Russian asset, I mean, totally,” Clinton said. “They know they can’t win without a third-party candidate.”

President Trump weighed in on on the dispute Saturday afternoon, urging a third party Green Party candidate to run in 2020, which would benefit him by peeling off Democratic voters.

“Crooked Hillary Clinton just called the respected environmentalist and Green Party candidate, Jill Stein, a ‘Russian Asset.’ They need a Green Party more than ever after looking at the Democrats disastrous environmental program!” Trump tweeted.

While it’s unclear why Clinton initiated this fight, the bad blood between her and Gabbard goes back to 2016, when Gabbard quit her post as a Democratic National Committee vice chair so she could endorse Clinton’s primary opponent, Sen. Bernie Sanders (I) of Vermont.

Gabbard is an unconventional Democrat, whose message of an isolationist foreign policy and willingness to buck the party establishment has gained her fans among the far right. She’s a frequent guest on Fox News, often Tucker Carlson’s show. She went on Friday night to talk to Carlson about her clash with Clinton.

She has also gained a following with some white nationalists. A neo-Nazi website called Daily Stormer said it deserved credit for getting her the support necessary to qualify for the first two debates.

But the main reason many Democrats, including Clinton, are wary of her is because she’s a favorite topic on Russian websites and social media.

“Hillary is absolutely going to continue to call balls and strikes as she sees them because while she knows she was on the receiving end of it in 2016, our 2020 nominee will face the same threat,” said Philippe Reines, a former Clinton adviser.

Gabbard was back on the campaign trail Saturday, holding two town hall meetings in Iowa, including one in the town of Clinton.

David Weigel in Ames, Iowa and Michael Scherer contributed to this story.