Senator Bernie Sanders, an Independent from Vermont, left, speaks next to Christian Smalls, founder of the Amazon Labor Union (ALU), during an ALU rally in the Staten Island borough of New York, U.S., on Sunday, April 24, 2022.Victor J. Blue | Bloomberg | Getty ImagesAfter years of declining influence, unions are having a resurgence. Employees from companies across the country are increasingly organizing as a means of asking for more benefits, pay and safety from their employers.Between October 2021 and March of this year, union representation petitions filed at the NLRB increased 57% from the same period a year ago, according to recent data from the U.S. National Labor Relations Board. Unfair labor practice charges increased 14% during the same period.More than 250 Starbucks locations filed petitions, and after notching a first win late last year, 54 Starbucks company-owned stores have formally organized. Workers at an Amazon warehouse in New York City recently voted to form the first union at the second-largest U.S. private employer and join the Amazon Labor Union. Google Fiber contractors in Kansas City successfully voted to unionize their small office in March becoming, the first workers with bargaining rights under the one year-old Alphabet Workers Union. These efforts are resonating with the broader public. A Gallup poll conducted last September showed 68% percent of Americans approve of labor unions — the highest rate since 71% in 1965.So why are unions becoming popular again?The Covid-19 pandemicExperts say the biggest factor was the Covid-19 pandemic.”The pandemic was the wakeup call or the catalyst that has prompted two perspectives: ‘is there another way to work and live?’ and the relationship between employers with workers,” said former NLRB chairman and current Georgetown Law professor Mark Pearce. “The vulnerable workers — they were not only scared, they were pissed.” “Covid was everything,” agreed Jason Greer, a labor consultant and former field examiner agent for the NLRB. “A lot of people said ‘I’m seeing my family members die and my friends die and we were suddenly faced with our own mortality but a lot of organizations still expected you to work just as hard or harder.'”As governments and employers imposed new restrictions to slow the spread of the pandemic, and demand spiked for services that let people do more from home, like e-commerce and grocery delivery, employees were faced with new challenges. Retail workers had to enforce mask-wearing and check vaccination status. Delivery and warehouse employees worried that they weren’t equipped properly with the right safety gear.”We saw a tidal wave of activism during the first months of the pandemic,” said Jess Kutch, co-founder and co-executive director of Coworker.org, which assists workers in organizing efforts. The group saw more use of its website in a three-month period than all of its previous years combined. “That was a clear indication that far more people were wanting to speak out than previously.”Many of these workers communicated about their struggles through digital channels, which became the natural disposition for all communication during Covid lockdowns. “When you track the push from within Apple, the push within Google, I think a lot of this has to do with embracing digital channels like Slack,” Greer said. “It’s been this perfect storm of people having more access to each other with tools in such an environment.”At the same time, the huge disruptions in buying patterns drove record profits at companies like Amazon and Google, who were equipped to fulfill the needs of a society suddenly forced to stay home. The distance between leadership and rank and file widened as a result, experts said, adding that in many cases executive salaries increased while employees’ wages stayed the same. In one example of an insensitive exec that went viral, Better.com CEO Vishal Garg laid off 900 employees, or about 9% of the company’s staff, over a brash Zoom video conversation in early December.A supportive political environmentOrganizers are also taking advantage of the supportive political environment they’ve seen in decades.President Joe Biden vowed to be the “most pro-union president ever” and has been very vocal about his support for the PRO Act, which aims to make the unionization process easier and less bureaucratic. Early in his term, Biden revamped the National Labor Relations Board, firing former President Donald Trump’s NLRB general counsel Peter Robb shortly after taking office. Biden then installed the new general counsel Jennifer Abruzzo, a former union attorney, who has been using her enforcement powers pretty widely.”It’s significant that Biden’s first action was to do that because he was sending a message to labor that the NLRB, even with its weaknesses, should not be dismantled from within,” said Pearce.Biden has taken aim at captive audience meetings, a common practice used by companies to reject union efforts. The NLRB settlement with Amazon in December sent a message to other companies and union organizers alike that the NLRB will be aggressive in enforcing violations.The president met with 39 national labor leaders on Thursday, including Christian Smalls, who heads the Amazon Labor Union, and Laura Garza, a union leader at Starbucks’ New York City Roastery. Contagious successThe media attention on employees organizing — successful or not — also fuels a domino effect, experts said. They don’t even need to be successful, said Kutch.For instance, employees at an Apple retail store in Georgia told CNBC last month they were inspired in part by Amazon employees who tried to unionize a warehouse in Bessemer, Alabama. Derrick Bowles, who is on the Apple Retail Union organizing committee, said he has a “massive amount of respect” for what the Bessemer employees did — even though that union drive hasn’t yet been successful. In Seattle, Starbucks organizer Sarah Pappin, 31, said that she’s been in contact with unionizing Verizon retail workers.”We all kick around between the same crappy retail jobs,” Pappin said. “This is the moment where we’ve all realized that it actually kind of sucks everywhere, so let’s just make a stand at one place and prove it.”In early May, Starbucks said it would hike wages for tenured workers, double training for new employees and add a tipping feature to credit and debit card transactions. However, it said it won’t offer the enhanced benefits to workers at the more than 50 company-owned cafes that have voted to unionize. “We’re seeing social justice combined with worker justice, and it’s not only catching fire but it’s getting results,” Pearce said.Richard Bensinger, a union organizer with Starbucks Workers United and a former organizing director of the AFL-CIO believes most of the pro-union workers are in their early 20s, prompting him they are part of a “Gen U” for unions. According to Gallup data from 2021, young adults ages 18 to 34 approve of unions at a rate of 77%.These younger workforces see each other’s victories as inspiration for their own, experts said.Kutch and Pearce gave the example of the Google Walkout, which she said “was an important moment not just for the tech sector but for the history of the labor movement.”In Nov. 2018, thousands of Google employees in more than 20 offices around the world staged walk-outs to protest an explosive New York Times report that detailed how Google shielded executives accused of sexual misconduct, either by keeping them on staff or allowing them amicable departures. Organizers described it as “a workplace culture that’s not working for everyone,” and listed several demands. Some of them ended up becoming California law, while others were incorporated into a settlement with shareholders who had sued the company over its handling of the incidents.It showed that employees from a large corporation could organize by way of internal chatter, spreadsheets and emails — in a matter of days, Kutch said, adding that many people saw the images through social media.”Shouting out in the park about the injustices or holding up a banner in front of a facility has a whole lot more effect when it’s on the internet,” Pearce said. CNBC’s Annie Palmer also contributed to this report.