Thousands of marchers protested Saturday against Walmart building a store in the Chinatown area of Los Angeles.

The verbal fight against the supermarket chain came as no surprise, as it followed a more tamed attempt at getting the same point across only a few days prior. Unions in the Los Angeles area have been putting politicians under pressure to deny or return the retailer's campaign donations in order to stop Walmart's attempts at expanding in large cities.

Prior to Saturday's march, three people at the 2013 Los Angeles mayor's race refused to take any donations given on behalf of Walmart. This was their way of reacting to a letter signed by 11 union officials and sent to candidates and officials in Los Angeles, to encourage them to reject or return Walmart offerings.

"We're not going to get every elected official to agree to this overnight, but we're going to build on it and continue to demand it of them," said Maria Elena Durazo, executive secretary-treasurer of the Los Angeles County Federation of Labor, who signed the letter.

Union officials hope that this pressure on politicians will encourage Walmart to pay its workers higher wages and also pressure smaller stores to do the same.

Despite recent protests, Walmart heads say the unions will not discourage them from continuing to open neighborhood stores in urban areas. They also said that they will continue to speak with local customers about what they believe the stores' benefits are.

"The vast majority see Walmart as part of the solution when it comes to things like jobs, healthier foods and sustainability," company spokesman Steven Restivo said in an email. "We remain committed to serving customers here."

Walmart disagrees with protestors who say that its wages in California are too low and believe that they are competitive with industry's wages.