WASHINGTON — With a $1.9 trillion economic aid package on the brink of passing Congress and the pace of vaccinations picking up, some economists, Republican lawmakers and Wall Street traders are increasingly raising a counterintuitive concern: that the economy, still emerging from its precipitous pandemic-induced drop, could be on a path toward overheating.

The Biden administration rejected that argument again on Friday. Despite a stronger-than-expected jobs report, the president and his aides said there was still a long way to go to ensure the benefits of the recovery flow to workers hardest hit by the pandemic, who are predominantly people of color.

Passing President Biden’s recovery plan, they said, remains essential to a full and equitable recovery.

“Black workers are still facing an economic crisis,” Janelle Jones, the chief economist at the Labor Department, said in an interview. “We cannot talk about recovery and taking our foot off the gas while these workers are still facing economic devastation.”

For those workers, Ms. Jones said, “It really matters what we do in the next two weeks.”

But some Republicans, saying the economy no longer needs an injection of nearly $2 trillion in borrowed money, continued to urge Democrats to pare back the stimulus package, which Senate Democrats have modified slightly in recent days.

On Wall Street, there were signs this week that investors are beginning to believe that such a large package could spur some resurgence in inflation, though there is little to suggest that markets anticipate a return to the dangerous levels of the 1970s, as a few prominent economists have warned.

Mr. Biden continued to press his case for the full $1.9 trillion plan in afternoon events at the White House, meeting with top economic advisers and then hosting a round-table discussion to build support for the plan.

“Today’s jobs report shows that the American Rescue Plan is urgently needed,” the president told reporters before the start of the meeting with aides. He said the jobs gains in February were likely because of a $900 billion relief bill Congress and President Donald J. Trump approved in December, and he warned that without more assistance, further gains “are going to be slow.”

“We can’t go one step forward and two steps backward,” Mr. Biden said.

In the Senate, lawmakers began voting on a flurry of amendments to the bill, which could pass as soon as Saturday. Democrats huddled to find agreement on last-minute tweaks to the legislation to appease centrists in their caucus.

Republicans on Capitol Hill have locked arms against the bill. Some senators say their opposition comes, in part, from fears that Mr. Biden’s plan would pour too much money into a recovery that is accelerating on its own.

The Biden plan “risks overheating an already recovering economy,” Senator Rob Portman, Republican of Ohio, said this week on the Senate floor, “leading to higher inflation, hurting middle-class families and threatening long-term growth.”

Mr. Portman cited inflation concerns voiced in recent weeks by the Harvard economist Lawrence H. Summers, a Treasury secretary under President Bill Clinton and top economic aide to President Barack Obama. In an email this week to reporters, an aide to Senator Mitch McConnell of Kentucky, the Republican leader, highlighted reports of rising fears of American inflation among top British officials.

Mr. Biden has ambitious ideas for other big programs this year, including a major infrastructure package, further fueling concerns about economic overheating. The administration insists those plans would not be inflationary because they would be offset by tax increases on the wealthy and corporations, but some economists and Democrats say they could end up being at least partly financed by deficit spending.

Inflation expectations have climbed gradually since the November election, and moved up slightly after a strong jobs report on Friday. Even so, commonly cited measures show that investors are penciling in price gains just a bit above 2 percent in coming years. That is consistent with the Fed’s stated goals, and not the kind of destabilizing, runaway price gains that the economy experienced a generation ago.

Still, the fact that investors are expecting growth to surge this year has mattered for markets.

Bond yields have been climbing since the start of 2021, as investors anticipate a little more inflation and a rapid economic bounceback. That adjustment has caused stock prices to drop in recent weeks. Higher interest rates make it more expensive for companies to borrow and can attract money away from the stock market.

As investors look for a pickup in growth and slightly faster price increases, watchers of the Federal Reserve have begun to expect that it might begin to slow its big bond purchases, which it has been using to bolster growth, and raise interest rates sooner than had been anticipated.

The central bank has promised to leave interest rates near zero until the economy has achieved full employment and inflation is above 2 percent and expected to stay there for some time. If markets expect the economy to reach those goals sooner rather than later, that could be seen as an expression of optimism.

“If you look at why they’re moving up, it’s to do with expectations of a return to more normal levels, more mandate-consistent levels of inflation, higher growth, an opening economy,” Jerome H. Powell, the Fed chair, said of rates during a recent congressional testimony.

But markets are forward-looking: The economy has a long way to go before it will be back to full strength. Administration officials have vowed not to be distracted by improvements in high-profile numbers, like overall job growth, and instead keep pouring fuel on the recovery until historically disadvantaged groups have regained jobs, income and the benefits of other measures of economic progress.

Job gains last month came in above economists’ forecasts, but it would take more than two years of hiring at the current level to return the labor market to its employment level in early 2020.

In addition, while all demographic groups continue to feel economic pain, the fallout has not been evenly spread. Employment for Black workers remains nearly 8 percent below its prepandemic level, while employment for white workers is down about 5 percent. Black workers tend to lose jobs heavily during recessions, then gain them back only after a long stretch of job growth.

Ms. Jones, the labor department economist, said the administration was determined to accelerate the recovery for marginalized workers, noting that Black workers, in particular, took years longer to recover from the 2008 financial crisis — a delay that left lasting scars on those households.

“Nothing about the state of the world means that Black workers have to face a large amount of labor market slack,” she said. “We can choose the benchmark that we actually want to restore the economy to.”

But even some economists who have favored substantial government spending in the past, most prominently Mr. Summers and Olivier Blanchard of the Peterson Institute for International Economics, have warned that Congress risks overdoing it by pouring so much money into the economy at a time when it is already healing.

Mr. Blanchard posted on Twitter on Friday morning, comparing the big fiscal package with a snake swallowing an elephant: “The snake was too ambitious. The elephant will pass, but maybe with some damage.”

Mr. Summers warned in a recent opinion piece in The Washington Post that the Biden package is going to pump far more money into the economy than it is missing, arguing that the monthly amount “is at least three times the size of the output shortfall.”

One major concern is that as the government pushes money into an economy that does not need so much support, too many dollars will end up chasing too few goods and services.

Fed officials do not believe that big spending is going to fundamentally change the way consumers and businesses think about prices. Inflation has been low for decades, and businesses often report that they have little pricing power in a world where technology and globalization makes competition fierce.

Inflation is likely to jump temporarily this year as economic data rebounds from its very low readings last year and people spend their savings on missed vacations and restaurant dinners. But Fed officials have said there is little to suggest that such an increase would last.

“I think it’s a constructive thing for people to point out potential risks,” Mr. Powell said this week during a question-and-answer session. “But I do think it’s more likely that what happens in the next year or so is going to amount to prices moving up but not staying up — and certainly not staying up to the point where they would move inflation expectations materially above 2 percent.”