I'll bite on this one, as someone who considers himself roughly poised between a "liberal" and a "leftist." The Democratic Party does not "support a genocide." Liberals, by and large, do not "support a genocide." Many liberals, as well as the current Democratic administration, have been critical of Israel's government. Netanyahu is a right-wing thug is not popular at all among liberals, even Jewish liberals. The administration has attempted to use its political power and influence to change and moderate Israel's conduct, though I know it has not done so nearly strongly or publicly enough for pro-Palestinian leftists. But the administration is walking a fine line because it must also keep in mind, in an election year, the large number of "liberals" (and persuadable moderates) who either support Israel or are conflicted about whose side to take in the never-ending Middle Eastern debacle. The administration also has to consider that complete withdrawal of weapons and aid to Israel would strengthen and embolden Iran and its proxies in the Middle East. And whatever anyone thinks about Israel's callous campaign of death and destruction directed at Palestine and now Lebanon, no one (at least no one reasonable) thinks Iran is the "good guys" or is anything but a bitter geopolitical enemy of the US.
So what leftists should realize and acknowledge about Gaza and Israel is that even if you think the situation is morally simple and straightforward that it is nothing close to politically straightforward and simple. But instead, not only do leftists not acknowledge that the situation is politically complicated, they castigate the entire Democratic Party as "supporting a genocide," despite any reasonable person recognizing that this is unfairly reductive at best and outright deceptive at worst. It is simply naive and unrealistic to think that, in an election year, with so much at stake, Democrats should torpedo their electoral prospects simply to take the moral high ground on the Israel/Palestine issue. That is the continuous problem with leftists: they would rather be right than win. If your goal is to win the moral argument, by all means continue to accuse the Democratic Party of "supporting genocide," something that helps push leftist voters away. But if your goal is to save as many innocent Palestinians and Lebanese as possible, then we need to focus for now on supporting the only presidential candidate and party who have shown the remotest willingness to care about Palestinians and push back against Israel, rather than the party who will gleefully stand aside as Israel nukes Gaza to the ground then builds a shopping mall on the ruins. The attempts to move the party and electorate leftwards on the issue can come after that.