It’s 100% on them. They lost. That’s how democracy works. They didn’t allow a real primary. Their candidate sucked. Their messaging sucked. They ended up with the biggest loss in decades, losing all three branches of government and the popular vote. This is a failure on every level and they don’t get to blame voters.
Each child born produces as much CO2 as 71 people going vegan for life. That ignores all the other ways humans pollute. Given that 130M babies are born each year, even if the entire planet went vegan right now (forever), it would only offset the next 324 days. If you care about the environment at all, you would focus all of your ire on the the real danger: countries with high birth rates.
However I suspect this has nothing to do with the environment for you. There is a duplicitous tactic employed by vegans which seeks to hijack the environmental movement for moral aims. People such as yourself have a moral problem with eating meat, and you know that many others care about the environment, so you attempt to wed the two. I am of course happy to be proven wrong.