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MIAMI BEACH (CBSMiami/AP) — While Republicans and Democrats in Washington deeply divided over how to deal with climate change, the mayors of more than 250 cities are taking a stand.

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On the final day of the U.S. Conference of Mayors on Miami Beach, they unanimously backed an ambitious commitment to have their cities run entirely on renewable sources, such as wind and solar, in two decades.

The symbolic resolutions were seen as a pushback against President Donald Trump on climate change and immigration.

“Mayors have been involved in the frontline of climate and energy issues for so long, but the president’s actions have really just ignited the excitement of mayors and citizens who want to get to do a whole lot more,” said Steve Benjamin, a Democratic mayor of Columbia, South Carolina, who proposed the resolution with three other mayors.

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Most mayors also signed a deal to do their part to uphold the terms of the Paris climate accords, even after the Trump administration pulled out of the agreement. They also strongly rejected plans to increase immigration enforcement and vowed to persuade federal lawmakers to reinstate a popular $3 billion program (Community Development Block Grants) that funds local projects across the country. Trump proposes eliminating the grants.

The clean-energy resolution is one of the many measures that will be sent to Congress and the White House hoping to influence legislation. It was proposed by Democratic mayors in the Republican-dominated states of South Carolina, Texas, Utah, and Iowa.

In Washington, Republicans and Democrats remain deeply divided over how to deal with climate change. But cities and states are slowly shaping policies to fight floods and add renewable sources of energy. More than 25 U.S. cities such as San Diego and Salt Lake City have already adopted the clean-energy policy, and six smaller cities including Aspen, Colorado, and Burlington, Vermont, have reached goals of generating 100 percent of the energy through renewable sources.

Traditional energy sources still dominate, with many cities saying they need their states to pass legislation to smooth the transition.

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(© Copyright 2017 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)