WASHINGTON — The coverage debate over elevating the federal minimal wage to $15 an hour is the newest fault line between Democrats, who largely assist the thought, and Republicans, who usually oppose such a pointy enhance as dangerous for enterprise.

However additionally it is revealing new fissures within the Republican Get together, which is straining to attraction to its company backers, a few of whom consider that greater than doubling the minimal wage would minimize deeply into their income, and the working-class wing, which fueled President Donald J. Trump’s rise and would stand to achieve from a pay enhance.

After many years of both calling for the abolishment of a federal minimal wage or arguing that it shouldn’t be raised, Republicans are starting to bow to the realities dealing with the occasion’s populist base with proposals that acknowledge the wage ground should rise. President Biden is more likely to attempt to capitalize on that shift as he tries to ship on his promise to boost the minimal wage, even when it doesn’t make it into the $1.9 trillion assist package deal due to a ruling Thursday evening by the Senate parliamentarian.

For years, Republicans have embraced the financial arguments that have been laid out in a letter this month to Congress by Individuals for Tax Reform, the Membership for Progress and different conservative teams that promote free enterprise. They level to research that assert mandated wage will increase would result in job losses, small-business closures and better costs for shoppers. They usually make the case that the financial trade-offs will not be price it, saying that extra jobs could be misplaced than the variety of folks pulled from poverty and that these in states with a decrease value of dwelling — usually conservative-leaning states — would bear the brunt of the fallout.

In 2016, as Republicans moved additional to the correct, reasonable candidates reminiscent of Jeb Bush, a former Florida governor, and Senator Marco Rubio of Florida, argued forcefully that the federal minimal wage didn’t should be raised above $7.25, which is the place it nonetheless stands in the present day. Mr. Bush mentioned the matter of wages needs to be left to the personal sector, whereas Mr. Rubio warned concerning the danger of constructing staff extra expensive than machines.

However Republicans have at instances grappled with the difficult politics of a place that so clearly sides with enterprise pursuits. Within the 2012 presidential marketing campaign, Mitt Romney, the Republican nominee, mentioned that he believed that the federal minimal wage ought to rise in keeping with inflation, as measured by the nationwide Client Worth Index.

And after arguing early on in his 2016 marketing campaign that wages have been already too excessive, Mr. Trump later mentioned he might assist a $10 minimal wage.

That’s the quantity that Mr. Romney, now a Republican senator from Utah, and Senator Tom Cotton, Republican of Arkansas, launched in a plan that may step by step elevate the minimal wage to $10 over 4 years after which index it to inflation each two years.

On Friday, Senator Josh Hawley, Republican of Missouri, went a step additional by matching the proposal that Democrats have made for a $15 minimal wage. His plan comes with a giant caveat, nevertheless, and would apply solely to companies with annual income of greater than $1 billion.

“Megacorporations can afford to pay their staff $15 an hour, and it’s gone time they accomplish that, however this could not come on the expense of small companies already struggling to make it,” Mr. Hawley mentioned.

The proposal drew a pointy rebuke from David McIntosh, the president of the Membership for Progress, who instructed that Mr. Hawley was adopting dangerous insurance policies in a bid to attraction to Mr. Trump’s voters. He mentioned that his group wouldn’t assist Republicans who promoted minimal wage will increase and mentioned that they need to be pushing for payroll tax cuts to offer staff extra take-home pay.

“That is one other instance of his ambition driving him to those populist positions that utterly violate any rules he has about free markets,” Mr. McIntosh mentioned in an interview.

Whereas the speaking factors surrounding the minimal wage have remained largely the identical through the years, the politics are shifting partly as a result of the federal wage ground has stagnated for therefore lengthy — and a rising financial literature has instructed that the prices of upper wage flooring is probably not as vital as analysts as soon as anxious they could be.

After rising step by step over the many years, the minimal has held steady at $7.25 an hour since 2009. Costs have step by step elevated since then, so the hourly pay price goes a shorter distance towards paying the payments nowadays: Immediately’s $7.25 is equal to $5.97 in 2009 shopping for energy, adjusted by consumer price inflation.

Given how low it’s set, a comparatively small share of American staff really make minimal wage. About 1.1 million — 1.5 % of hourly paid staff and about 0.8 % of all staff — earned at or below the $7.25 ground in 2020.

States with the best share of hourly paid staff incomes at or under the federal minimal are sometimes Southern — like South Carolina and Louisiana — and skew conservative. About seven in 10 states which have an above-average share of staff incomes at or under the minimal wage voted Republican within the 2020 presidential election.

Whereas solely a slice of the work pressure earns at or under the minimal, lifting the federal base wage to $15 would bolster pay extra broadly. The $15 minimal wage would carry pay for some 17 million staff who earn lower than $15 and will enhance pay for one more 10 million who earn simply barely extra, primarily based on a current Congressional Budget Office analysis.

Nonetheless, elevating wages for as many as 27 million Individuals is more likely to come at some value. The finances workplace, drawing on outcomes from 11 research and changes from a broader literature, estimated that maybe 1.4 million fewer folks would have jobs in 2025 given a $15 minimal wage.

Some economists who lean towards the left have questioned the budget office’s conclusion.

In analysis that summarized 55 completely different tutorial research of episodes the place a minimal wage was launched or raised — 36 in america, 11 in different developed nations — Arindrajit Dube on the College of Massachusetts Amherst discovered that even very slim slices of staff who have been straight affected, a ten % enhance in minimal wage would possibly result in a 2 % loss in employment. Trying on the results for low-wage staff extra broadly, the fee to jobs was “minute.”

Newer work from Mr. Dube has discovered subsequent to no employment influence from state and local minimum wage increases.

But many Republicans have seized on the finances workplace’s job loss determine.

In a column titled “How Many Jobs Will the ‘Stimulus’ Kill?” Stephen Moore, an adviser and ally of Mr. Trump’s, and the conservative economist Casey B. Mulligan counsel that the $15 federal minimal wage will value one million jobs or extra. Mr. Moore mentioned in an electronic mail that they have been counting on the Congressional Funds Workplace’s estimate.

Nonetheless, quite a lot of financial officers emphasize that the fee to jobs of a better minimal wage will not be as massive as as soon as believed, and that the federal minimal wage has not stored up with inflation.

“Increased minimal wages clearly do assist the employees who’re affected,” John C. Williams, the president of the Federal Reserve Financial institution of New York, mentioned throughout a digital speech on Thursday. “There are some job losses,” however current proof means that it isn’t as many as as soon as anticipated.

There’s precedent for elevating the minimal wage towards $15, as a result of because the federal base pay requirement has stagnated, states and localities have been rising their very own pay flooring. Twenty states and 32 cities and counties raised their minimum wages simply at first of 2021, primarily based on an evaluation by the Nationwide Employment Legislation Mission, and in 27 of these locations, the pay ground has now reached or exceeded $15 an hour.

The drive towards $15 started in 2012 with protests by fast-food staff and was initially handled as one thing of a fringe thought, however it has gained momentum even in states which can be closely Republican. Florida — which Mr. Trump received in November 2020 — voted for a ballot measure mandating a $15 minimal wage by 2026.

Like in lots of these native instances, Democrats are proposing a gradual enhance that may part in over time. Janet L. Yellen, the Biden administration’s Treasury secretary and former Fed chair, instructed in response to lawmaker questions after her affirmation listening to that the lengthy runway might assist mitigate any prices.

“It issues the way it’s carried out, and the president’s minimal wage shall be phased in over time, giving small companies loads of time to adapt,” Ms. Yellen wrote.