Sen. Kamala D. Harris (D-Calif.) speaks at a town hall meeting on April 5 in Sacramento. (Rich Pedroncelli/AP)

As college graduation season descends upon the nation, so likely will come the boycotts. College students have a history of staging protests of commencement speakers they deem problematic, usually because of their politics, art or business dealings.

Given that many of the boycotts come from more-liberal students, conservatives often use this occasion to argue that college campuses tolerate free speech only if it is liberal in its leanings. A March Gallup poll said most — 61 percent — college students say the climate on their campuses prevents some people from expressing their views because others might find them offensive.

This year's commencement season, however, features a particularly high-profile boycott. Sen. Kamala D. Harris (D-Calif.) was scheduled to deliver the keynote at Saturday's graduation ceremony at the University of California at Berkeley. But on Monday, she announced that she was skipping the event in support of a labor strike.

“If we are going to live up to our ideals as a nation, it’s critical we focus on economic equality and economic justice,” she tweeted Monday. “One key is making sure everyone has access to a good job, with fair wages, and safe working conditions.”

According to SFGate:

Thousands of service workers with the American Federation of State County and Municipal Employees, AFSCME, walked off the job at all 10 UC campuses Monday in protest of what they said was the University of California’s practice of hiring contractors and displacing longtime employees.

Preventing students from hearing from one of the most popular voices in the Democratic Party and forcing them to listen to their chancellor on one of the biggest day's of their educational career might seem like a surefire way to lose fans — if not voters. But Harris, whose name regularly appears on the shortlist of possible Democratic Party 2020 candidates, may be playing the long game. Appealing to the concerns of working-class Americans will be a core issue for Democrats in 2020, given that one of the more prominent post-2016 election narratives was about how appealing Donald Trump was to white working-class voters.

Showing solidarity with blue-collar workers will be a key campaign strategy for individuals looking to lead the Democratic Party moving forward. Harris's move could become one that workers will expect others on the both sides of the aisle to follow in the future.

Of course, quite a few other politicians will be giving commencement speeches at colleges and universities across the country this month. Actress Cynthia Nixon, who is running against New York's incumbent Democratic governor, Andrew M. Cuomo, spoke Saturday at New York City's Helene Fuld College of Nursing. And Sen. Susan Collins (R.-Maine), who reportedly flirted with a gubernatorial run earlier this year, is speaking at Colby College on May 27. The list goes on and on.

Graduation ceremonies — like many events on college campuses — have become increasingly political, and as we move closer to our next elections, what politicians says in commencement speeches may be less important than what their presence at the events says about their values.