The El Paso shooter is a product of years, if not decades, of environmentalist hysteria.  When a person carefully reads his manifesto, it is clear he's nothing more than a version of the Unabomber Ted Kaczynski, the man who tried singlehandedly to stop technological advances by mailing explosive devices that killed three men and seriously injured several others.

The words from the El Paso shooter himself put the blame squarely on all that is allegedly doing harm to the environment because of the American way of life:

The American lifestyle affords our citizens an incredible quality of life. However, our lifestyle is destroying the environment of our country. The decimation of the environment is creating a massive burden for future generations. My ideology has not changed for several years. My opinions on automation, immigration, and the rest predate Trump and his campaign for president.

He also states in his online manifesto:

If we can get rid of enough people, then our way of life can become more sustainable.

If the left can blame Sarah Palin for the shooting of Gabby Giffords because Palin once used the term "putting a target on their backs" for political opponents, then why can't the entire Democratic party and liberal ideology be blamed for so many years of criticizing industrial America for the El Paso shooters' mass killing?  Furthermore, he has exposed a contradiction in left-wing Democratic ideology that is all for open borders and the massive influx of foreigners into the country yet promotes the idea that people are doing irreparable harm to the environment.  This is a blatant discrepancy as wide as the Grand Canyon.  How can you square this circle?  The simple answer is, you can't. 

Like most ideologues (and liberals), the El Paso shooter is blind to the holes in his thought processes with an inability to see the forest for the trees.  Carbon emissions have been steadily declining for decades in the United States while significantly increasing in other countries, especially in China and India, yet they are never excoriated for pollution and harm to the environment as much as the United States.  This all ties in to the demonizing and utopian thinking by the Left of everything leftists see as bad in their pursuit and maintenance of political and governmental power. 

Over time, the liberal agenda is clearly growing more and more extremist, as manifested by the 2020 Democratic presidential candidates.  As their rhetoric grows more shrill with each passing year, it seems logical that people hearing their catastrophic and fatalistic messages would eventually turn to violence.