It is March, nearly two months into the Trump presidency and the left’s grass-roots protest against it. “The resistance,” as it’s called in some corners, kicked off with a by-the-thousands flurry — women’s marches around the country, airport protests, town hall inundations. But the next round of town hall protests won’t come for another few weeks, and the midterms — the first real chance to prize Republican backsides from congressional seats — are more than a year and a half away. What the movement faces now is the challenge of sustaining its energy long enough to translate it into electoral change. But the left doesn’t necessarily have all the elements that the tea party did, elements that translated into electoral success in 2010. While the Trump resistance movement undoubtedly has enthusiasm, a number of structural differences from the conservative grassroots movement could lead to challenges down the road.

And the left has indeed been looking to the tea party template for inspiration. The authors of the now-popular “Indivisible” guide for the grassroots left to organize against Trump, specifically cite the success of the group in their call to action: “The authors of this guide are former congressional staffers who witnessed the rise of the tea party. … We saw them organize locally and convince their own MoCs [members of Congress] to reject President Obama’s agenda. Their ideas were wrong, cruel and tinged with racism — and they won.”

But what made the tea party successful, according to Theda Skocpol, a Harvard professor whose field studies of the tea party movement became a 2011 book, was a particular climate on the political right. “We thought of the tea party as a set of several intersecting forces that were leveraging each other and helping to build each other’s clout to change and use the Republican Party,” she said. Self-organizing grass-roots groups, top-down professional advocacy and money groups, such as FreedomWorks and Americans for Prosperity, along with right-wing media, swirled together to make the movement a success, according to Skocpol. It remains to be seen if the climate on the left will prove to be hospitable for the growth of a similarly effective movement.

At the grass-roots level, there’s reason for the left to be optimistic. While there’s not yet enough data available to draw finer conclusions about the left-wing resistance, Skocpol called the scale of the women’s marches around the country “pretty remarkable.” But she tempered this with caution. “What I don’t know is how much sustained organizing is going on in states and districts across the country.” The most active tea party groups Skocpol encountered held monthly meetings, invited speakers and formed committees to stay informed on what was happening in their state legislatures. “I know that the Indivisible site lists thousands of groups, but I don’t think we know how persistent they are,” she said.

The left also faces challenges related to the demography of its traditional constituencies – younger, more diverse — that tend to vote less than the older, white base of the Republican Party, particularly in special elections and midterms. Where the left’s movement could go wrong, Skocpol said, was being too fixated on demonstrations. “It’s got to transfer to votes.” Using the base’s energy to register left-leaning voters and turn them out to the polls will be the ultimate test of grassroots success.

On a larger organizing scale, the tea party’s affiliation with professional advocacy groups helped amplify their cause and at times helped find money for candidates that lived up to the group’s ideals; Scott Brown’s special election to the U.S. Senate in 2010, taking Ted Kennedy’s seat, was funded in part by a tea party PAC. Where the left could stumble — particularly the far left — is with a lack of cooperation with big-money donors and organizations. “Groups such as FreedomWorks were absolutely vital,” former tea party organizer Ben Howe wrote in an email. “People have short attention spans and are fickle with their motivation levels. Having a funded group whose entire job is to organize events for voters to attend kept the ball moving at all times.

In response to right-wing accusations that the left’s protesters have been paid by billionaire funder George Soros, it’s now en vogue in left-leaning circles to joke about picking up one’s Soros check post-protest. But the joke disguises a real optics problem the resistance movement could face, the idea that receiving big money or help from left-establishment structures is tantamount to selling out.

“I think the reality is that people like George Soros invest in some really worthy progressive causes,” said Sarah Dohl, an Indivisible board member. “If we’re serious about this — and we should be serious about protecting our values — then we need to think long and hard about taking those dollars and doing the most we can with them to make the most difference.” Indivisible, currently a 501(c)(4) non-profit organization, is weighing its options, Dohl said, contemplating among other things, PAC status.

Another consideration from a top-down organizing perspective is that internecine struggles on the left stemming from the combative 2016 primaries could rear their heads once again within the resistance movement. “We have talked about that because one of things we do talk about at length in the guide is the importance of, just like the tea party did, not just pressuring Republicans but asking our good blue members to stand up boldly,” Dohl said. She pointed to Indivisible group efforts in California to pressure Sen. Dianne Feinstein for her votes approving a number of Trump cabinet appointees. “I think there’s some question about how all that will play out,” Dohl said.

Skocpol’s view of that strategy was blunter. “Trying to force Democrats in Congress who have no leverage to just say ‘no’ to everything would be a diversion to building a broader anti-Trump coalition,” she said. The tea party had offered what she called a “beguiling model” but she said, “the Democrats are much weaker in the states.” Howe, the former tea partier, also cautioned that the Democrats would do well to find an “inspirational movement leader that helps focus all the individual groups towards one specific purpose.” Disparate tea party groups sometimes ended up going wayward, Howe said, buying into the birtherism conspiracy theories and leaving the rest of the movement to deal with the fallout. “With no inspirational movement leader(s) defining what it was, we were constantly on defense dealing with groups all over the country over which we had no control,” he said.

The tea party’s symbiotic relationship with right-wing media was an important cohesive component of its success. In their 2011 paper on the tea party, Skocpol and her co-authors noted the importance of conservative talk radio and bloggers, but also assigned a great deal of import to the role Fox News played in the movement’s success: “The best way to understand Fox News’ role is as a national advocacy organization actively fostering a social protest identity.”

What remains to be seen is how the left’s protest identity might be sustained on a national level in a similar way. Sites such as Daily Kos and podcasts like Pod Save America provide a certain ideological home to those in the resistance, but as far as television, America’s most beloved, albeit fragmenting, medium, liberals have no true equivalent home to Fox News. The closest they’ve gotten is attention from Rachel Maddow’s MSNBC show.

“She features our groups and their photos and videos almost every night,” Dohl said. “It’s been a really powerful energy builder for our group; they get geared up when they see themselves.”