Thousands of fast-food workers demanding a $15 an hour wage walked out in dozens of cities at 6 a.m. today, marking the start of a year-long campaign aimed at mustering the political power of 64 million low-wage workers in the upcoming presidential election.

In the largest rally to date, workers from Burger King, Wendy's, McDonald's, KFC and other restaurant chains joined the likes of home care, child care, grocery clerks and other low-wage workers to stage walk outs in 270 cities nationwide, according to MSNBCParticipants will also be protesting at 500 city halls.

In New York City, rallies are being held in Harlem, the Financial District and Brooklyn in support of efforts to raise the minimum wage to $15 an hour, according to CBS New York.

In Los Angeles, the local protests were organized by Service Employees International Union, and include fast-food, home-care and child-care workers, along with other "underpaid" employees, according to CBS Los Angeles.

New York City Mayor Bill de Blasio was present at the rally in Downtown Brooklyn, saying that it doesn't make sense for anyone to expect someone to get by in NYC on less than $15 an hour.

"Is this the America we believe in? When someone works all day long and they still can't get by," he said. "Does anyone believe that it's easy to get by in New York City on less than $15 an hour?"

Sen. Bernie Sanders also took part in a rally in Washington, D.C., where he praised the efforts of the strikers.

"What you are doing, and workers around the country are doing, you're having a profound impact," he said. "You should be very proud of what accomplished and now we have to finish the - $15 bucks and a union."

Conversely, most Republican candidates oppose raising the federal minimum wage from $7.25/hr, saying it would hurt job growth and would usher higher taxes, according to USA TodayThese rallies are expected to play a huge role in upcoming local, state and national elections, with workers saying they'll support any candidate of any party who supports their cause.

A recent survey by the National Employment Law Project (NELP) found that most unregistered voters would sign up and registered voters would be most likely to vote if a candidate backs a $15 hourly wage. These groups represent 48 million potential voters in total.

"People are going to be looking for that in a candidate" and will vote for politicians "that are responsive to their economic well-being," said NELP Executive Director Christine Owens.