2024年4月18日，美国纽约警方进入哥伦比亚大学校园，对占领学校草地的学生进行清场，并逮捕了100多名学生。这些学生以在校园内扎帐篷的方式抗议美国政府默许以色列国防军在加沙地区的暴行。近几日，局势持续升级，哈佛大学、耶鲁大学、密歇根大学和麻省理工等多所美国高校的学生自发组织起来，声援被政府逮捕的学生，并要求校方与在巴以冲突中获利的雷神公司和洛克希德马丁公司切断经济联系。

这不禁让人联想到1968年，哥伦比亚大学“学生争取民主社会组织”（SDS）采取同样方式抗议越战，并遭到纽约警方暴力清场。那时，林登·约翰逊政府不断升级越南战争，美国国内反战情绪高涨。有线电视信息技术的发展，使得反战舆论进一步升级。越战是美国历史上第一个被“直播式报道”的战争，大量美国民众坐在家里的沙发上就能看到越南战场上的惨状，反战情绪开始集中爆发，间接或直接导致民主党内分裂。在民主党反战派批评、民主党内部对越战分歧加剧和国会面临巨大压力的背景下，林登·约翰逊在1968年新罕布什尔州民主党总统初选中宣布退选。

如今，拜登政府寻求连任遇到的困难和1968年的约翰逊政府不相上下。与56年前相似，以色列国防军在加沙地带大规模空袭和全面封锁导致严重的人道主义危机、大量平民被杀戮的视频在Instagram、TikTok等新媒体平台上大量传播，引发国际社会的关注，在美国舆论界掀起巨大风暴。

在巴以冲突中，美国扮演着重要的角色。作为以色列的盟友，几十年来美国对以色列政府在政治、经济、军事、文化四大领域进行无条件支持。在政治上，美国在联合国安理会多次否决停火协议，不遗余力地支持以色列，成为和平解决巴以冲突的最大障碍。在经济上，美国对以色列的扶持力度极大。美国国会研究服务中心（CRS）发布的《美国对以色列的援助》报告显示，美国政府1946年至2023年1月对以色列的经济援助高达1586.65亿美元。后来经济援助逐渐被军事援助替代,1985年起美国每年向以色列提供30亿美元的军事援助，导弹防御拨款被单独列出。2023年11月3日，哈马斯对以色列发动袭击不到一个月，美国众议院火速通过了一笔143亿美元的对以军事援助。在文化上，一些学者认为，美国媒体界、演艺界、学界受到支持犹太复国主义运动的资本集团严重渗透，绝大部分批评以色列的声音都受到了审查。

长期以来，在犹太复国主义运动游说集团的运作下，美国国家利益与以色列国家利益被深度捆绑，而这种捆绑受到了进步左翼群体的强烈批评。这些进步左翼群体通过组织示威游行、占领公共设施、抵制亲以产品等方式抗议拜登总统在巴以冲突中的立场。

以史为鉴，在寻求连任方面，拜登政府面临的最大变数是如何处理新一轮巴以冲突。而目前面临的最大挑战，是如何在保证以色列公共事务委员会（AIPAC）和反诽谤联盟（ADL）为首的犹太复国运动游说团体支持其竞选的同时，最大程度地减轻因过度偏袒以色列而失去亲巴勒斯坦年轻左翼群体选票的负面影响。

不可忽视的是，进步左翼群体的支持对拜登能否连任至关重要。回顾2020年大选，拜登政府得以击败特朗普政府的主要原因，在于成功获得受年轻左翼群体青睐的持民主社会主义立场的伯尼·桑德斯和进步主义阵营四位女性众议员（The Squad）的背书。在2020年大选民主党初选阶段，拜登多次受到来自党内进步阵营对其“温和”立场的批判，在美国政治极化严重的大背景下，正是因为后续有伯尼·桑德斯等左翼领袖呼吁其支持者以“必须阻止特朗普连任”为目标积极参与投票，拜登才得以避免2016年因选民参选率低而导致民主党败选的情况再次出现，并在普选票和选举人票上都击败了特朗普。有分析认为，学生群体对拜登的总统连任至关重要，“民主党需要非常高的年轻选民投票率才能赢得选举，否则形势将对共和党有利”。

而此轮巴以冲突发展到现在，已经引发拜登在年轻选民中的支持率下降。如果拜登继续忽视进步左翼的诉求，2024年美国总统大选时大概率会出现和2016年相似的场景，即选民参与率较2020年大幅下降，大量年轻进步左翼选民选择不参与投票，以抗议拜登政府在巴以问题上的立场。在共和党出现“特朗普”化、极右翼化的今天，这种在民主党票仓内出现的“不参与”倾向对拜登选情极为危险。

此外，穆斯林裔美国人群体对拜登的不满也在不断加剧，而这部分群体对拜登选举起到关键作用。有分析认为，密歇根、宾夕法尼亚等关键摇摆州的穆斯林裔选民帮助拜登赢得2020年大选。但去年巴以冲突爆发一个月后，美国智库《阿拉伯裔美国人研究所》发布调查报告称，阿拉伯裔美国人对拜登的支持率从2020年的59%跌至冲突爆发后的17%。2024年3月5日，美国“超级星期二”初选投票日前，明尼苏达州和密歇根州等穆斯林人口占多数的州发起“不表态”运动，表达对拜登的抗议。4月初，白宫的斋月晚宴遭到诸多美国穆斯林精英群体代表的强烈反对与抗议，拜登与穆斯林群体的紧张关系给今年的大选选情带来更多不确定性。

但美国对以色列的支持仍在持续，此轮巴以冲突并未有缓解的态势。4月24日，美国总统拜登正式签署了总金额950亿美元的对外援助拨款法案，其中包括对以色列的263亿美元援助。同日，以色列继续猛烈轰炸加沙中部地带，造成至少27名巴勒斯坦人死亡，其中包括10名儿童。下一阶段的巴以冲突将如何发展尚未有定数，但毫无疑问，它在美国社会引发的争议以及舆论的分裂已经对拜登连任造成了严重影响。

On April 18, the New York City police entered the campus of Columbia University to clear out students occupying the school's west lawn and arrested more than 100.The students were protesting the actions of the Israeli Defense Forces in the Gaza Strip. They erected tents on campus and settled down for a long-term sit-in.In recent days, the situation escalated, as students from several American universities, including Harvard, Yale, Brown and MIT, spontaneously gathered in support of the arrested students and demanded that the schools sever economic ties with Raytheon and Lockheed Martin, which profit from the Israeli-Palestinian conflict.

This inevitably brings to mind 1968 when the Students for a Democratic Society, or SDS, at Columbia University protested the Vietnam War in a similar manner and were violently evicted by the New York City police. At that time, President Lyndon B. Johnson was escalating the war, and antiwar sentiment was high in the United States. The development of cable television technology further escalated antiwar sentiment. The Vietnam War was the first war in American history to be televised, allowing a large number of Americans to see the horrors of the battlefield from their sofas at home.Antiwar sentiment began to concentrate and either directly or indirectly led to divisions within the Democratic Party. Against the backdrop of criticism from antiwar factions within the party, increasing internal divisions and immense pressure from Congress, Johnson announced his withdrawal from the 1968 New Hampshire Democratic presidential primary.

Currently, the challenges facing President Joe Biden, who is seeking re-election, are comparable to those of the Johnson administration in 1968. Similar to Vietnam 56 years ago, large-scale airstrikes and the comprehensive blockade by the Israeli Defense Forces in Gaza have created a severe humanitarian crisis. Videos of civilian casualties have been widely circulated on social media platforms such as Instagram and TikTok, attracting international attention and sparking a huge storm in the sphere of American public opinion.

The United States is playing a significant role in the Israeli-Palestinian conflict. As an ally of Israel, it has unconditionally supported the Israeli government politically, economically, militarily and culturally for decades. Politically, the United States has repeatedly vetoed cease-fire agreements in the United Nations Security Council, staunchly supporting Israel and becoming the biggest obstacle to peace in resolving the conflict.Economically, the United States has provided massive support to Israel. A report by the Congressional Research Service revealed that the U.S. government provided nearly $158.7 billion in economic assistance to Israel from 1946 to January 2023. Economic aid has gradually been replaced by military aid. Since 1985, the United States has provided $3 billion in military aid to Israel annually, with appropriations for missile defense separately listed.On Nov. 3, less than a month after Hamas launched its attacks on Israel, the U.S. House of Representatives passed a $14.3 billion military aid package for Israel. Some scholars believe that the American media, entertainment industry and academia have been heavily infiltrated by capitalists supporting the Zionist movement, and the majority of voices critical of Israel have been suppressed.

For a long time, Zionist lobbying groups have tightly linked America's national interests with those of Israel, drawing significant criticism from progressive leftist factions. Progressive leftist groups have been orchestrating protests, occupying public spaces, initiating boycotts against pro-Israel goods, and voicing dissent against Biden's stance on the conflict.

Drawing lessons from history, the biggest problem facing Biden in seeking re-election is how to deal with the new round of the Israeli-Palestinian conflict — how to maintain the support of the American Israel Public Affairs Committee, the Anti-Defamation League and other Zionist lobbying groups, while minimizing the negative impact of excessively favoring Israel on the votes of young leftist Palestinian groups.

Undoubtedly, the backing of progressive leftist factions is pivotal for Biden's re-election bid. Reflecting on the 2020 election, one of the primary factors behind Biden's victory over Trump was the endorsement of the democratic socialist stance favored in young leftist circles by Bernie Sanders, as well as support from four progressive congresswomen famously known as “The Squad.” During the Democratic primary stage of the 2020 campaign, Biden faced criticism from progressive factions within the party for his “moderate” stance.Against the backdrop of intense political polarization in the United States, it was encouragement from leftists such as Bernie Sanders that induced their followers to engage actively in voting under the banner of “Defeat Trump” and enabled Biden to sidestep a recurrence of the 2016 scenario, where low voter turnout resulted in the Democratic Party's defeat. Instead, Biden secured victories in both the popular vote and the electoral college vote, prevailing over Trump.Some analysts posit that the backing of the student demographic is of paramount importance for Biden's bid for re-election. They argue that the Democratic Party relies heavily on a robust turnout of young voters; otherwise, the balance could tilt in favor of the Republicans.

As the current Israeli-Palestinian conflict unfolds, support for Biden has waned among young voters. Should Biden persist in disregarding the appeals of the progressive left, the 2024 U.S. presidential election may witness a situation reminiscent of 2016, characterized by a notable decline in voter turnout compared with 2020. A considerable portion of young progressive left voters may opt not to participate. In the current Republican Party, which has veered toward a more Trumpish right-wing position, the phenomenon of uncommitted voters within the Democratic Party's base poses a grave threat to Biden.

Further, discontent in the Muslim-American community toward Biden is steadily escalating. This demographic holds significant sway in Biden's electoral fortunes. Analysts assert that Muslim-American voters in pivotal swing states like Michigan and Pennsylvania were instrumental in securing Biden's victory in the 2020 election. But a month following the onset of the Israeli-Palestinian conflict last year, a survey by the Arab American Institute, a prominent American think tank, found a significant decline in support for Biden among Arab Americans, dropping from 59 percent in 2020 to 17 percent after the conflict erupted.On March 5, ahead of the “Super Tuesday” primary, states with sizable Muslim populations such as Minnesota and Michigan initiated the “uncommitted” movement, signaling their discontent with Biden. In early April, the White House's Ramadan dinner encountered staunch opposition and protests from numerous representatives of the American Muslim elite, further complicating this year's election prospects.

Despite all this, the unwavering support of the United States for Israel persists, and the current Israeli-Palestinian conflict shows no sign of abating. On April 24, President Biden officially signed a $95 billion foreign aid appropriations bill, allocating $26.3 billion in aid to Israel even as Israel continued its airstrikes in central Gaza, killing at least 27 Palestinians, including 10 children.The trajectory of the next phase of the Israeli-Palestinian conflict remains uncertain, but it is undeniable that the controversy it has generated in American society and the polarization of public opinion it has created have significantly impacted Biden's chances for re-election.