Nurses strike on September 12, 2022, outside North Memorial Health Hospital in Minnesota.

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CNN  — 

Between strikes by nurses, teachers and maybe railroad workers, and new union efforts gaining steam at Starbucks, Amazon, Apple and elsewhere, big labor is having a big moment.

On the nation’s freight railroads, strapped workers who must be on call seven days a week are at an impasse with railroads that have seen record profits during the Covid-19 pandemic. Unions representing more than 60,000 workers are on course to strike on September 16 unless Congress steps in, which seems unlikely.

The strike – which could halt nearly 30% of the country’s freight – could put a devastating new kink in the nation’s supply chain, snarling shipment of food and other products.

In Minnesota, about 15,000 nurses walked off the job Monday, part of a three-day strike to draw attention to their standoff with management over short-staffing, among other things.

It’s not the pay, it’s the working conditions. That’s the same story teachers in Columbus, Ohio, told when they went on strike to start the school year. American workers want not only to be paid better but also to be treated better. That’s the overriding theme of high-profile labor disputes this year.

CNN’s Chris Isidore has been covering all things labor for CNN, and much of what’s in this analysis comes from his many must-read stories:

A headache for Democrats heading into November. There’s some irony in the fact that these flexes of labor muscle come as Democrats, labor’s natural ally, control the White House and both chambers of Congress.

President Joe Biden has exhausted his options for preventing the rail strike after mandating a cooling-off period and appointing a special board to solve the impasse earlier this year.

RELATED: Biden and Cabinet officials in touch with rail companies and unions as threat of strike looms

Isidore notes the Biden-appointed emergency board came up with a middle road that would give rail workers a 24% pay hike over five years, but many of the unions have not yet signed on.

Union leaders – like Dennis Pierce, president of the Brotherhood of Locomotive Engineers and Trainmen, and Jeremy Ferguson, president of the union that represents conductors – warned Democrats in Congress not to intervene. They say a strike is the only way to improve their working conditions.

“This is a chance for the Democrats to stand up for something they say they support, the working class and labor,” Ferguson said.

Support for labor unions has risen dramatically. In 2009, less than half of Americans, 48%, said they approved of labor unions in an annual Gallup survey. This year, more than two-thirds of Americans, 71%, said they approved of labor unions, the most support unions have seen since 1965.

However … At the same time, the Gallup survey suggests most nonunion workers in the US have little interest in joining a union – which will make it hard for unions to grow.

Isidore wrote about the few penalties companies face for actions that cut down on organizing. Starbucks has closed stores where union votes occurred or were planned. It’s fired employees at a Memphis location for working with a local TV station reporting on union efforts.

The National Labor Relations Board, which oversees organizing votes at most US businesses, won a court ruling that the employees had been fired for their union activity, according to Isidore, but Starbucks is appealing. It’s hard to see how that ordeal won’t have a chilling effect on other efforts to unionize Starbucks locations.

The number of Americans who belong to a union has fallen just as dramatically. Back in 1983, when the Bureau of Labor Statistics started gathering information on union membership, around 20% of American workers belonged to a union. In 2021, that figure was just over 10%. Union membership declined by 241,000 last year.

Unions are more powerful in the public sector. About a third of public-sector employees, 33.9%, belonged to a union in 2021 – we’re talking about everyone from teachers to firefighters and police.

Far fewer private-sector workers, 6.1%, belonged to a union.

Unions are more powerful in blue states. Southern states and red states, many of which have so-called “right to work” laws that make it more difficult for unions to organize, have fewer union members. In the most unionized states, New York and Hawaii, more than 22% of workers belonged to a union last year. In the Carolinas, the two least unionized states, membership was below 3%.

Democrats suffer when they lose union households. Barack Obama won 58% of union households in 2012. Hillary Clinton got just 51% of union household support in 2016 when she lost the Electoral College to Donald Trump in 2016. Biden was back up to 56% support among union households in his 2020 victory.

Union households made up about one-fifth of American voters in those elections, according to exit polls.