I’d like to know what Democratic Party you’re referring to, and how I can support them, because the one in my country (the United States) is nothing like you described. They would sooner give Trump a third term than let anyone with even the most moderate left wing views near the levers of power. Look what they did to Bernie, look what they did to Nina Turner, look what they did to Kori Bush, and look what they almost did to Zorhan.
The Democratic Party hates leftists just as much if not more than the republicans do, and that’s because we threaten their uniparty hegemony. Democrats may be your enemy, but the Left is not.