From the Women's March on Washington to the March for Science, the first year of the Trump administration saw an increase in highly-publicized mass demonstrations, leading to the sense that the president's policies are mobilizing people with progressive beliefs to defend their views in the streets.

Now, a Washington Post-Kaiser Family Foundation poll reported by The Washington Post on Friday provides the numbers to confirm that narrative.

The poll, the most in-depth look at U.S. protesters in more than a decade, found that 20 percent of Americans have joined a political rally or street demonstration since the start of 2016. For 19 percent of them, that rally was the first they had ever attended.

According to the poll, dissatisfaction with Trump was a major motivator for demonstrators: 70 percent of them disapproved of the job the president is doing compared with 30 percent who approved. Half of demonstrators attended events at least partly because of Trump.

Concerns about the environment were also a key motivating factor for American rally-goers. Thirty-two percent of demonstrators who attended a rally in the past two years did so to express their views on "the environment and energy issues," according to the results. It was the issue that attracted the second-largest percentage of demonstrators, after women's rights at 46 percent.

A vast majority of those environmental demonstrators supported environmental protections and action on climate change. Deeper analysis of the data shows that 29 percent of rally-goers attended "an event in support of protecting the environment or fighting climate change" and only two percent raised their voices "in support of increasing access to oil, natural gas, or coal."

The data did not indicate how many environmental protestors were new to the game or how many were specifically motivated by the Trump administration's reversal of environmental regulations and denial of climate science.

However, vocal opposition to Trump's environmental agenda has been a big part of the anti-Trump "resistance" from day one.

Days after the inauguration, the Badlands National Park made headlines for tweeting out facts about climate change after Trump suspended the National Park Service's Twitter usage because of tweets unfavorably comparing the size of his inauguration crowds to Obama's.

The April 2017 March for Science, a response to Trump's disregard for scientific facts, mobilized a group that has traditionally preferred the lab to the street.

"Scientists have not been eager to get politically involved, but in the face of unceasing attacks and organized denial, they're putting their credibility to good use," 350.org co-founder Bill McKibben said of the march.

Polls have also suggested that the majority of Americans' views on climate change do not match the rhetoric of the Trump administration. For example, a 2017 poll by AP-NORC and the Energy Policy Institute at The University of Chicago found that 61 percent of Americans thought climate change was a threat that the federal government should act to mitigate.

The Washington Post poll questioned a random sample of 1,850 U.S. adults and was conducted in January and February of 2018.

Overall, it has important implications for the upcoming midterm elections which will determine which party controls the House and Senate. Eighty-two percent of demonstrators, who are largely upset with Trump, said they would be "certain" to vote in 2018.