Couldn't far left progressives run their own candidates to win their own elections on issues without siphoning unreciprocated one-way support from the Democrat party? Given the toxic outcomes of supporting purity testers who give ultimatums similar to yours on political issues completely unrelated to the average voters life, theres likely no mainstream party that would align with a platform of virtue signallers that dont intend to create any meaningful policy, so to claim your position is popular is somewhat is a misnomer. Saving people is a popular concept, sure, but it's not easily perceptible to the rest of us that the group taking the strategy to ensure the most suffering for the Palestinians possible in our voting cycle is the one attempting that feat.