Yes but can he win back the communists after disparaging them ?
Or will the communists support Trump ?
Biden'''s comments downplaying China threat to U.S. fire up pols on both sides
Communists are an extremely small section on the America electorate and do not have a united party, voice or position on how they would vote in 2020. For example, some may be sympathetic to the Sanders campaign in the democratic party, whilst others will be intensely hostile because it draws support away from actual socialist and communist party as a bailout for the Democrats as a pro-capitalist and pro-corporate party. So you'd get a range of responses.
The Communist Party USA will probably endorse Joe Biden in order to remove Trump, as they have endorsed the Democratic candidate for President since they stopping running their own candidates in 1988. So they have endorsed all of the following Democratic Party candidates in the past: Michael Dukakis (1988), Bill Clinton (1992 & 1996), Al Gore (2000), John Kerry (2004), Barack H. Obama (2008 & 2012) and Hillary Clinton (2016).
In terms of how marginal they are, the CPUSA has somewhere around 5,000 to 10,000 members. To give that some perspective, that is compared to the democratic socialists of America with 66,000 members, the Green Party of the United States with around 250,000 members, the Libertarian Party with 609,234 members and the Democratic Party with 45,715952 members. Put another way, if there are 10,000 members in the CPUSA, for every communist, there are 6-7 socialists, 25 greens, 61 libertarians (if you round up) and 4,571 Democrats. Both the CPUSA and the Democratic Socialists of America have experienced a surge in support in response to Trump winning in 2016 and some Sanders voters defecting away from the Democratic Party. But this surge won't make them a major competitor in U.S. elections anytime soon. Rather it is a marginal improvement from historic lows as the far left hasn't really recovered from the collapse of communism and the dissolution of the U.S.S.R. The best way to think about the past 30 years is that the far left have been a life and death battle to maintain a supply of political oxygen. The Current problems in American politics will raise their profile, but it remains to be seen if they can consolidate it in to a permanent presence in U.S. politics at a state or federal level.
Of course the CPUSA isn't the only far left party, but probably the biggest by a large margin. There are several
third-party candidates standing in 2020 and some of them could be placed in the far left:
* Gloria La Riva (President) and Leonard Peltier (Vice President) for the "Party for Socialism and Liberation" and the "Peace and Freedom Party".
* Jeff Mackler (President) and Heather Bradford (Vice President) for "Socialist Action".
* Joesph Kishore (President) and Norissa Santa Cruz (Vice President) for "Socialist Equality Party"
* Howie Hawkins (President) adn Angela Nicole Walker (Vice President) for "Socialist Party USA" and "Solidarity". Hawkins may win the Green Party's presidential primary for 2020 which would give him a boost.
* Alyson Kennedy (President) and Malcolm Jarrett (Vice President) for the "Socialist Worker's Party".
If Hawkins wins the Green Primary he will do well (the Greens got 1,457,218 votes or 1.07% of the vote in 2016) . Glora La Riva ran in 2016 and got 74,401 votes (0.05% of the vote nationally). So aside from Hawkins, any of these candidates would be lucky to pick up 0.5%-1.0% of the vote in 2020, particuarly as they will split an already small share of the vote between them.
A tiny minority of Communists may vote for Trump but it will be a rarity because Trump doesn't share even a "progressive" agenda. Some will argue that voting for trump makes things worse in america and so "better" for encouraging the discontent of the workers and advancing the revolution. All you need to know is this is the same logic that the German Communist Party applied in the 1930's to the Nazis and they ended up in concentration camps on the assumption that "first Hitler, then us!". So most communists are not going to be that stupid again.