I don't think Republicans are against a clean environment, but I don't think Democrats are as pro environment as they claim to be. Or, maybe Democrats are so anti-right, they can't even support a bill that would have positive environmental impact, because the order came from our President.
Trump is imposing tariffs on goods from overseas in an attempt to stimulate domestic manufacturing of goods. New factories means new jobs, but new factories also create pollution. The US regulates emissions and groundwater contamination much more strictly than China and many other countries. Opening factories in the US, and closing factories overseas puts the amount of pollution factories produce within American legal jurisdiction.
If a Democrat proposed a tax on foreign goods from countries who do not meet the US's environmental standards as a means to pressure manufacturers to relocate factories to the US, where there is complete oversight of emissions, Democratic voters would rally behind them.