President Barack Obama responded last night to Wisconsin Gov. Scott Walker’s signing of the state’s recently-passed “right-to-work” bill, reported The Huffington Post. The bill has been criticized by many pro-labor advocates as merely being another anti-union law.

“It’s no coincidence that the rise of the middle class in America coincided in large part with the rise of unions -– workers who organized together for higher wages, better working conditions, and the benefits and protections that most workers take for granted today,” Obama said in a statement.

“So it’s inexcusable that, over the past several years, just when middle-class families and workers need that kind of security the most, there’s been a sustained, coordinated assault on unions, led by powerful interests and their allies in government.”

Walker’s signing of the bill makes Wisconsin the 25th state to adopt anti-union laws, which ban workers from joining unions and paying union dues as part of their employment. Republicans love these anti-union laws, selling them under the guise of being “pro-freedom” laws.

Unions protect workers from unfair labor practices and ensure that workers have a voice that will be heard by politicians and companies. Unions also ensure that workers receive fair wages from their employers.

Obama’s statement continues:

Wisconsin is a state built by labor, with a proud pro-worker past. So even as its governor claims victory over working Americans, I’d encourage him to try and score a victory for working Americans -– by taking meaningful action to raise their wages and offer them the security of paid leave. That’s how you give hardworking middle-class families a fair shot in the new economy –- not by stripping their rights in the workplace, but by offering them all the tools they need to get ahead.

Obama is correct for asserting that labor unions are crucial for middle-class growth and economic expansion. With this new bill, Republicans are continuing the charge to dismantle unions. Anti-union laws don’t help anyone but corporations and the wealthy. History clearly illustrates the benefits that unions give to American workers.

When union membership was at its peak in America during the mid-20th century, America’s total wealth was more evenly distributed to workers, and income inequality was at an all-time low. According to a recent TruthOut report:

As membership increased after 1936 during the Great Depression, peaking at 33.4 percent in 1945 and staying about the same until 1960, the top 10 percent’s share of wealth fell. At a height of 46.3 percent in 1932, the share of wealth held by the richest tenth fell to 31.5 percent by 1944, remaining stable till about 1980. As union membership steadily declined after 1980, the wealthiest Americans saw their share of riches surge.

Union membership brings amazing benefits to American workers, and the middle-class once flourished. Ever since conservatives began attacking labor unions, the middle-class has suffered.