Folks that have lived in "socialist" nations such as Venezuela, Bolivia and many others would vehemently oppose anything even appearing to "lean heavily left". Don't believe me? Go ask them. Because unless one is hooked into the ruling party, they all know that the rest of society loses, and loses big. It's exactly what Central Americans are leaving behind as they head north in caravans of thousands. It's why Cubans will risk the ocean on a raft. Pretty picture in the short run, disastrous future. Always play the long game and strive for the common good.
Why does the world insist on repeating the failed systems of others in their own context?
If something sounds too good to be true, it usually is; especially when it comes from a political party.
Smart, controlled immigration has always been and will always be necessary in a healthy society that wants to have an identity.