The U.S. Senate has entered a marathon voting session to decide the fate of a massive budget package central to former President Donald Trump’s legislative agenda. Dubbed the One Big Beautiful Bill Act, the proposal has sparked intense debate, with its passage still uncertain after weeks of tense negotiations.

Despite holding a majority in both chambers of Congress, Republicans remain divided over how far to go in cutting welfare programs in order to fund an extension of Trump-era tax breaks. The proposed legislation spans nearly 1,000 pages and has become a flashpoint in the broader debate over fiscal responsibility and social safety nets.

As lawmakers engage in a prolonged “vote-a-rama” — a Senate process involving a flurry of back-to-back votes on amendments — the session is expected to last up to 20 hours and extend into Tuesday morning.

Elon Musk Renews Criticism

Adding to the drama, Elon Musk, a former close Trump ally, has ramped up criticism of the legislation, calling it “insane.” Musk condemned Republicans who support the bill despite campaigning on promises to reduce federal spending. “This would be the largest debt increase in American history,” he warned, noting the national debt already stands at $36 trillion. The bill, if enacted, would add another $3.3 trillion, according to estimates.

Musk also hinted again at launching a new political party and criticized the subsidies his own companies received under government programs. Trump, in response, took aim at Musk on his Truth Social platform, suggesting the Department of Government Efficiency (DOGE), which Musk once headed, should examine the vast subsidies the entrepreneur has benefited from. “Without them, Elon would probably be packing up for South Africa,” Trump quipped.

Tight Vote, Fierce Debate

Senators spent Monday moving between chamber votes and behind-closed-doors meetings to address unresolved disputes. One key amendment, introduced by Florida Senator Rick Scott, proposes deep cuts to Medicaid—a move estimated to impact up to 20 million Americans’ health coverage.

Senate Majority Leader John Thune defended the amendment, noting its delayed implementation: “It doesn’t take effect until 2031. So how can it be blamed for immediate coverage losses?”

Democrats have strongly opposed the bill, particularly the proposed reductions in healthcare and social spending. Senator Adam Schiff called it “terrible,” and expressed doubts about whether Senate Republicans could meet Trump’s preferred timeline for passage—by July 4.

The Senate narrowly advanced the bill over the weekend in a 51-49 vote, with two Republicans breaking ranks to oppose the measure. One of them, Senator Thom Tillis of North Carolina, later announced his retirement, citing frustration with political leadership. “Too many politicians care more about power than the people they represent,” he said.

The White House swiftly rebuked Tillis, with Press Secretary Karoline Leavitt declaring his criticism “just wrong.” She added that Trump remains “confident” the bill will land on his desk by Independence Day.

Procedural Hurdles and Political Risk

On Sunday, Democrats stalled the bill’s momentum by forcing Senate clerks to read the entire text aloud—a process that lasted 16 hours. Despite such tactics, Republicans aim to pass the final Senate version early Tuesday morning.

With a razor-thin margin, Republicans can afford no more than three defections. If that threshold is crossed, Vice President JD Vance is expected to cast the tie-breaking vote.

Once passed, the bill must return to the House of Representatives for final approval, possibly as early as Wednesday. However, internal GOP divisions could derail the plan, particularly among members of the House Freedom Caucus, who argue the bill adds over $650 billion to the deficit.

“That’s not fiscal responsibility,” the caucus said in a social media post. “It’s not what we agreed to.”

Massive Implications

Democrats in both chambers oppose the extension of Trump’s $3.8 trillion in tax breaks, especially when paired with steep welfare reductions. Analysts at the non-partisan Congressional Budget Office estimate that the bill could leave nearly 12 million Americans without health insurance.

As debate continues into the night, the fate of Trump’s “big beautiful bill” remains uncertain—caught between ideological rifts, budget realities, and the ticking clock of a self-imposed deadline.