Your morning coffee at Starbucks could soon come with a union label.

Employees at more than 200 Starbucks locations nationwide have filed petitions for union elections, seeking representation by Service Employees International Union (SEIU) affiliate Workers United. Associates at several stores have already opted to join the union.

This burst of barista organizing activity has energized a labor movement in desperate need of good news. Recent data from the Bureau of Labor Statistics shows that union membership in the private sector remains near historic lows, stubbornly resistant to labor leaders’ past efforts to turn the tide.

But the success of labor’s Starbucks strategy is far from guaranteed. Organizers face significant hurdles, especially when employees discover that union promises made during an organizing campaign can be dumped as quickly as a bitter espresso.

Unions historically had little traction in the full- and limited-service restaurant industry. High turnover, combined with a younger workforce that desires flexibility over rigidity, made a poor match for organized labor’s 20th-century-value proposition. Ten years ago, the SEIU made an expensive play to change that, through a campaign called the Fight for $15.

Starting in New York City and then expanding to other cities, the union’s fighters for $15 claimed that fast food restaurants were abusive work environments. Rather than targeting a single company through what’s known as a “corporate campaign,” the union targeted an entire industry.

The solution, according to the SEIU, was a $15 minimum wage and union representation.

In the ensuing five years the union was successful in normalizing a $15 minimum wage, but it paid dearly for that public relations victory: Public filings show that SEIU spent north of $100 million on its Fight for $15 campaign.

Today, the union has failed to achieve its goal of a national $15 starter wage; last year, eight Senate Democrats joined every Senate Republican in opposing it. The SEIU also has a near-zero success rate organizing local unions in fast food restaurants.

The Starbucks campaign is in many ways a repudiation of the Fight for $15. While both campaigns are reliant on positive PR, the Starbucks organizers are willing to do what SEIU’s corporate staffers on the Fight for $15 were not: Organize a union store by store, without spending $100 million on high-priced PR consultants and a top-down organizing strategy.

Starting with a Starbucks shop in Buffalo, NY, Workers United intentionally had one of its organizers get hired as a barista. (This is a controversial practice known as “salting.”)

Working from the inside out, this organizer recruited supporters for the union and eventually filed for an election. The national publicity associated with the Buffalo activity generated inquiries from other stores nationwide; union organizers gave these associates the support they needed to file for their own elections.

But this strategy has its limitations.

It’s fun to organize a union; it’s unpleasant hard work to negotiate a union contract. The Workers United organizers have everything riding on it: The negotiated contracts need to be substantially better than the status quo — no easy feat at a company such as Starbucks, known for its employee perks. Without a contract to prove it is a worthwhile investment to send a portion of their paycheck each month to the union, more workers will ask what they’re voting for.

The Starbucks strategy is also highly-dependent on a controversial decision by the union-aligned National Labor Relations Board (NLRB). The NLRB has allowed Workers United to organize employees store by store, rather than as a region with multiple stores. The union can cherry-pick store locations where it knows it has the handful of votes necessary to win.

This is a double-edged sword.

A union supported by a handful of workers can easily be removed (“decertified,” to use an NLRB term of art) when the workforce turns over and the new hires decide they’re not receiving bang for their buck.

Returning Starbucks CEO Howard Schultz has already indicated that union-represented workers may miss out on some benefits that the company is legally unable to provide employees with a collective bargaining agreement. This is surely not lost on non-union baristas.

Recent Gallup polling shows that unions enjoy their highest favorability marks among young people aged 18-34. One reason: Many in this age demographic are blissfully unaware of the “bad old days” of organized labor, when unions were most associated with malfeasance and corruption. These problems persist to this day: Witness the recent federal investigation into the UAW, which resulted in 17 convictions and put two of the union’s past presidents in prison.

Younger employees also have little direct experience with unions, which are difficult if not impossible to find in today’s private sector workplaces. For them, a union seems new, exciting and fun.

The reality of a union shop is different: Union contracts, often lengthy, dictate the minute details of your work life. (Michigan readers may remember the Ford-UAW master agreement from a few years back, which weighed 22 pounds and ran to more than 2,200 pages.)

This stifling 20th-century work environment is at odds with the choice and control that 21st-century workers seek — choice over when and how to work, and control over their earnings.

Starbucks employees deserve to make informed decisions on workplace representation free from union intimidation. A bill in Congress called the Employee Rights Act — introduced by Sen. Tim Scott, with support from Sen. Mitch McConnell and 26 of their colleagues — would guarantee workers a secret ballot vote and add new federal protections from union violence.

Those baristas who vote “yes” on union representation may find themselves pining for the freedom they had before the union got involved. The old adage still applies: If it ain’t broke, don’t fix it.