Sen. Elizabeth Warren (D-MA) – one of the most outspoken pro-union Democrat candidates – tweeted a series of messages on Labor Day, promising that unions will “rebuild” America’s middle class.

Warren used both of her verified Twitter accounts to tweet messages of support for unions and declared that they will “rebuild” the middle class.

“Unions built the middle class—and unions will rebuild the middle class,” Warren wrote. “If we want more good American jobs, then we need stronger unions and more power in the hands of the people.”

“I’m proud to be fighting alongside our unions,” she added, later suggesting that unions are “under attack”:

Unions built the middle class—and unions will rebuild the middle class. If we want more good American jobs, then we need stronger unions and more power in the hands of the people. I’m proud to be fighting alongside our unions. #LaborDay pic.twitter.com/uoAqIq9tH2 — Elizabeth Warren (@ewarren) September 2, 2019

No matter how many times strikers and organizers have been told "it’s too hard, give up now," they've persisted. When workers organize and fight together, they win—and they can change America. #LaborDay pic.twitter.com/0dVQuz4wWz — Elizabeth Warren (@ewarren) September 2, 2019

I’m in this fight for America’s workers every step of the way. #LaborDay pic.twitter.com/NDK8iohEOp — Elizabeth Warren (@SenWarren) August 30, 2019

Coming out of the Great Depression, labor unions helped build America’s strong middle class. As our families got richer, our country got richer – & labor unions were a big part of it. Today, unions are under attack, & we need to fight back so workers can make their voices heard. pic.twitter.com/kM66Rb3CRg — Elizabeth Warren (@SenWarren) September 1, 2019

Happy #LaborDay! Today we say loud & clear: unions built America’s middle class, & unions will rebuild America’s middle class. pic.twitter.com/GbzfDsa914 — Elizabeth Warren (@SenWarren) September 2, 2019

It is true that Warren has been one of the most outspoken supporters of the labor movement, despite membership declining across the board. It has dipped from 12.3 percent participation to 10.5 percent over the last decade, according to Illinois Public Media.

Pew Research Center also found that the “share of American workers who belong to labor unions has fallen by about half” during the past few decades, going from 35 percent in 1954 to 10.5 percent in 2018:

The actual number of union members was 14.7 million last year, according to the Bureau of Labor Statistics (BLS). In 2012, union membership hit its lowest point since the current data series began in the early 1980s, falling below 14.4 million, before turning modestly upward.

Warren joined airport food workers in a minimum wage protest organized by Unite Here at the Reagan National Airport in July, alongside Sen. Bernie Sanders (I-VT) – another notable pro-union Democrat candidate – and Mayor Bill de Blasio (D):

Warren is spending Labor Day campaigning in New Hampshire. She is expected to deliver remarks at a house party in Hampton Falls at approximately 2:30 p.m. Eastern.