WASHINGTON — President Biden’s passionate language on reducing gun violence, safeguarding access to abortion and protecting voting rights has lifted the hopes of progressives who were once wary of electing a traditionalist who champions compromise.

But now, as they look past the final push on a $3.5 trillion spending bill the White House has made its policy priority, they are growing more concerned that Mr. Biden’s actions will not be as bold as his tone — at least when it comes to some of their key issues.

The spending plan that Democrats are trying to get through Congress would be transformative, affecting almost every American at every stage of life, from free universal prekindergarten to coverage of elder care. It includes money to address not only social programs and the expansion of the social safety net, but also funds to address climate change.

But in order to take up some of the other issues Mr. Biden has framed as threats to the foundations of American democracy, he will have to confront arcane rules that guide the institution of the Senate that he reveres — and that so far he has made clear he does not want to pressure senators to change.

Privately, White House officials have been trying to assure activists that they plan to turn their attention in earnest to voting rights after their push on infrastructure is through at the end of the month. But that has done little to ease anxiety.

“I’m guardedly concerned,” said the Rev. Al Sharpton, who said he was nervous that Mr. Biden would not follow up his lofty statements and speeches with action. “There’s a difference between passion and marriage.”

Mr. Sharpton said he wanted the White House to pressure senators to support a “carve-out” in the filibuster to allow voting rights legislation to pass with a simple majority.

“They have not said they’re going to do that,” Mr. Sharpton said.

Marc H. Morial, the president and chief executive of the National Urban League, said that in private meetings, he had pressed the president and his senior aides to work to pass voting rights by any means necessary. “If you can’t find 10 Republican votes, then the filibuster must go, it must be carved out, it must be reformed,” he said. “It’s not more important than protecting American democracy.”

The response from the president and his top aides, according to Mr. Morial, has been muted.

“You don’t get much of a response,” he said. “I think there’s a reluctance to telegraph future moves.”

Mr. Biden has used soaring language to match the base’s passion on certain issues.

“Every life that is taken by a bullet pierces the soul of our nation,” the president said in May after a mass shooting in San Jose, Calif. He also referred to gun violence in America as an “epidemic” that required urgent action.

This month, after the Supreme Court declined to block a Texas law prohibiting most abortions, Mr. Biden called the decision an “unprecedented assault on a woman’s constitutional rights.”

And in a summer speech on voting rights, he framed the movement to suppress and subvert the right to vote as “an assault on democracy, an assault on liberty, an assault on who we are — who we are as Americans” and said it was “threatening the very foundation of our country.”

But the question remains: What comes next?

Mr. Biden is approaching a crossroads moment for his domestic agenda, where he has already had to trim back his policy goals on the minimum wage, electoral safeguards and criminal justice reform in the face of resistance from Republicans as well as members of his own party.

This month, the president admitted a stunning defeat for his gun-control agenda when he had to pull his pick to run the Bureau of Alcohol, Tobacco, Firearms and Explosives after he could not muster enough support for the nomination in the Democratic-controlled Senate.

Jen Psaki, the White House press secretary, has said that growing frustration among gun safety advocates should be “vented at the members of the House and Senate who voted against the measures the president supports, and we’d certainly support their advocacy in that regard.”

That is not a satisfying answer to many activists.

“We will have had two years with Democrats in full control, and if they end up breaking their promises on every one of those issues — from guns to voting rights to abortion rights — that seems inconceivable and should be inconceivable,” said Eli Zupnick, a spokesman for Fix Our Senate, a coalition of more than 80 organizations working to eliminate the filibuster. “But that’s what they’re on track to do unless they finally address the filibuster standing in the way.”

Stephen Spaulding, a senior counsel at Common Cause, said that engaged Democratic voters were attuned to the filibuster, the Senate’s signature procedural weapon that requires a 60-vote supermajority to advance most bills.

“They will have serious questions if it’s not reformed and there is no action to protect voting rights or reproductive rights, both of which are under attack in states across the country,” he said. “They will ask the question: ‘Why did you care more about a Senate rule than these priorities?’”

Even a pared-down voting rights bill that Senate Democrats have united around is unlikely to gain traction with Republicans, who have argued the legislation is a threat to their party.

Mr. Biden has criticized the filibuster, saying at his first formal news conference as president that it was being “abused in a gigantic way.”

But since then, he has said he does not want to press for reforms because that fight would distract from his agenda. “Wouldn’t my friends on the other side love to have a debate about the filibuster instead of passing the Recovery Act?” he said at a CNN town hall event in July. He also said he wanted to pass voting rights with bipartisan support, not by changing Senate rules.

“I want to make sure we bring along not just all the Democrats, we bring along Republicans who I know know better,” he said. “What I don’t want to do is get wrapped up right now in the argument whether or not this is all about the filibuster.”

The conversation has become unavoidable, even as the White House has tried to avoid it. In a round table meeting that senior White House officials held this month with women’s rights and reproductive health leaders, many participants raised the issue of the filibuster and asked whether Mr. Biden was going to be shifting his position, according to attendees. They received no response from the officials in attendance.

While many of them offered suggestions on how to fight the Texas abortion law, and encouraged legal action that the Justice Department took this month, all of them said that a legislative fix was ultimately necessary and that White House pressure would help.

“Long term, we need legislative intervention just as it’s needed on voting rights,” said Nancy Northup, the president of the Center for Reproductive Rights, who participated in the meeting. “It’s necessary to stop Texas from what it’s doing, but also long term to actually address this issue.”

A White House spokesman, Chris Meagher, said that “the president has made clear that voting rights, protecting a woman’s constitutional right to access safe and legal abortions as protected by Roe, and combating the scourge of gun violence are critical priorities for his administration.” Mr. Meagher added, “He will continue to engage with leadership on the Hill to prioritize legislation around these critical issues.”