The Senate signaled broad bipartisan support on Thursday for the next round of coronavirus stimulus checks to be more targeted.

The chamber voted 99-1 on an amendment from Sens. Joe Manchin (D-W.Va.) and Susan Collins (R-Maine) related to "targeting" the checks and making sure that "upper-income taxpayers are not eligible."

The vote is nonbinding and the budget resolution to which senators attached the proposal doesn't get signed into law. But the margin signals overwhelming support in the Senate for tightening the phase-out structure of the next round of checks as Congress crafts the COVID-19 relief bill that Democrats want to pass by mid-March.

"I don't think a single person on this floor would disagree to target the relief to our neighbors who are struggling to pay rent and put food on the table. This $1,400 will make a significant impact on their ability to get by. There are other families who have not missed a single paycheck as a result of this pandemic. It does not make sense to send a check to those individuals," Manchin said ahead of the vote.

Collins added that the "question before us is quite simple."

"Do we want stimulus checks to go to households with family incomes of $300,000 or do we want to target the assistance to struggling families who need the help and provide a boost for the economy?" she asked.

GOP Sen. Rand Paul (Ky.) was the only senator to vote against the amendment.

The measure doesn't specifically say how the checks should be further targeted, but the vote underscores that lawmakers are likely to make changes to currently offered plans.

President Biden's proposal would offer a $1,400 direct payment. It doesn't specify when the payments would start to be phased down, but previous rounds of direct stimulus checks have started to phase out at an income level of $75,000 for individuals.

Senators expressed bipartisan concern late last year at a House proposal that would change the amount of the stimulus check from $600, the amount of the latest direct assistance payment, to $1,400 but without changing the phase-out structure of the checks. That would have resulted in higher earners who had not been eligible for a check under the $600-level to get some payment under the $1,400 payment.

Sen. Bernie Sanders (I-Vt.), speaking from the Senate floor minutes before the vote, indicated that no one supported families with incomes of $300,000 per year getting a check. But he urged colleagues to support individuals who make up to $75,000 or couples who make up to $150,000 getting direct assistance.

"I do not oppose this amendment. I do not think anybody here wants to see people who make $300,000 get direct payments. Let's make certain that people who are making $75,000 per year or less do get their payments and couples making $150,000 or less do get their payments," he said.

Senators have been discussing making changes to the phase-out structure of the next round of stimulus checks amid broader concern that high-income earners would be eligible for payments unless Congress makes changes.

"I happen to agree that the Mnuchin formula on the cash payments should be revisited. The outcome of that Mnuchin formula was indefensible. It came through families in higher income categories. That wasn't the reason for the cash payments, to give already wealthy people some more money to invest in stocks. And so yes, I would be open to that," Sen. Dick Durbin (D-Ill.) told reporters late last week, referring to former Treasury Secretary Steven Mnuchin.

Those changes wouldn't necessarily change the amount of the check, or the income caps for getting a full payment. Rather senators have homed in on changing the speed at which the payments phase down for individuals who make above $75,000 or couples who make above $150,000.

The amendment was co-sponsored by Democratic Sens. Kyrsten Sinema (Ariz.), Maggie Hassan (N.H.), Jon Tester (Mont.), Jeanne Shaheen (N.H.), John Hickenlooper (Colo.), Mark Warner (Va.), Mark Kelly (Ariz.) and Independent Sen. Angus King (Maine), who caucuses with Democrats, as well as GOP Sens. Susan Collins (Maine), Rob Portman (Ohio), Shelley Moore Capito(W.Va.), Thom Tillis (N.C.), Bill Cassidy (La.), Mike Rounds (S.D.) and Mitt Romney (Utah).

Many of those Republicans are in the GOP group of 10 that met with Biden on Monday night to discuss their $618 billion coronavirus proposal. They sent Biden a letter Thursday where they highlighted concerns about the phase-out structure of the checks.

"Our goal is to target those direct payments to families with the greatest needs. As we expressed at our meeting, we do not believe that families making up to $300,000 per year need these direct payments, which they would have received under the CASH Act passed by the House of Representatives last December and which is currently included in your proposal," they wrote.

"We want to help struggling lower- and middle-income families as well as boost the economy; better targeting the direct payments would accomplish both goals," they added.

GOP Sens. Jerry Moran (Kansas) and Todd Young (Ind.) are part of the group that met with Biden, but are not formal co-sponsors of the amendment.

Tester told reporters that they left the measure open-ended to try to generate more support for the idea more broadly.

"I guess that beauty is in the eye of the beholder. It depends who you want to talk to. But I think the point of the amendment is it's negotiable so we can try to get some folks on board," Tester said.

Sen. Jon Ossoff (D-Ga.), who made the stimulus checks a key message in his recent Senate campaign, said he ahead of the vote that he wouldn't support the Manchin-Collins amendment.

"I'm advocating that we go big and that we deliver as much direct relief to the people as we can," he told reporters.

But he ended up voting for it.

The White House has signaled that while it's standing by $1,400 as the amount of the stimulus check that it's open to discussions about changing details of the payment structure.

“Further targeting means not the size of the check, it means the income level of people who receive the check and that’s something that has been under discussion. There hasn’t been a conclusion but certainly he’s open to having that discussion,” White House press secretary Jen Psaki told reporters at an afternoon briefing.

Members of the bipartisan group are also proposing an amendment signaling that they don't want the federal unemployment benefit to be above $300 per week. Biden's plan puts the federal unemployment benefit at $400 per week.

Warner, Hickenlooper and King, who co-sponsored the amendment on more-targeted checks, did not sign onto the one on the unemployment benefit. Young, who did not sign onto the checks amendment, did sign onto the unemployment proposal.

That amendment hasn't yet gotten a vote as part of the Senate's hours-long vote-a-rama.