“The choice to join a union belongs to workers alone,” President Joe Biden said on Wednesday.

The unionization drive among Amazon  (AMZN) – Get Amazon.com, Inc. Report workers has been picking up steam at such a rapid rate that, this week, even President Joe Biden threw his support behind the movement.

On April 4, workers at an Amazon warehouse on New York’s Staten Island overwhelmingly voted to unionize with the Amazon Labor Union (ALU) in the first union since Amazon launched in 1994. 

Amazon’s Workplace Practices Have Long Been Called Out

The decision came after years of worker complaints about mistreatment by the retail giant.

That included warehouse workers who reported urinating in bottles to not lose time and get flagged for being unproductive, to the firing of Christian Smalls, a former supervisor who was fired and described by an Amazon exec as “not smart or articulate” after trying to organize a small walkout over safety conditions.

As similar union efforts have been initiated from Alabama to Arizona and Virginia, Amazon has embarked on what many workers described as a ruthless anti-union crusade.

Reports emerged of Amazon reportedly removing pro-union fliers from break rooms at the Bessenger, Ala., warehouse, surveilling employee conversations and restricting employees access to the facilities to just 30 minutes before and after their shifts.

When workers at the Alabama warehouse voted to not join a union, the National Labor Relations Board found that Amazon improperly interfered in the first election and ordered a second. That one, held in March, was also rejected.

Prior to Wednesday, Biden had not directly named Amazon in his support for union workers. The closest he’d come was when, on Feb. 28, he posted a video expressing support for “workers in Alabama and all across America are voting on whether to organize a union in their workplace” on Twitter  (TWTR) – Get Twitter, Inc. Report.

Biden Is Behind Amazon Workers Now

“This is vitally important, a vitally important choice, as America grapples with the deadly pandemic, the economic crisis, and the reckoning on race,” Biden said at the time. “What it reveals the deep disparities that still exist in our country. And there should be no intimidation, no coercion, no threats, no anti-union propaganda.”

But by Wednesday, April 6, Biden took things a step further and directly told Amazon to “watch” the power of collective mobilization at a conference for thousands of labor leaders in Washington.

“The choice to join a union belongs to workers alone,” Biden said at the annual North America’s Building Trades Unions conference. “By the way, Amazon, here we come. Watch! Watch!”

Amazon did not immediately respond to TheStreet’s request to comment on Biden’s statements.

while he did not directly call on workers to form the union, this is the strongest support the pesident has made for Amazon union efforts thus far.

Will Biden’s Support Actually Change Anything?

Amazon has repeatedly denied engaging in union-busting and once said that it would “welcome the opportunity to sit down and share ideas with any policymaker” who proposes laws for better employee conditions. 

That said, constantly emerging accusations of employee surveillance have been catching global attention with snowballing effect over the last few weeks. 

In his speech, Biden called on Congress to pass the stalled Protecting the Right to Organize Act to limit employers’ ability to interfere with union efforts.

It is unlikely that Biden’s statements will be the ones to tip the scales in workers favor but, as the recent moves have shown, the unionization drive is getting more and more difficult for Amazon. Aand, in what can be a domino effect, it could make it harder for other tech and retail giants to ignore.

“Workers who join a union gain power, the power over decisions that affect their lives,” Biden also said. “When you’ve got a union, workers’ voices are heard and heeded.”