President Trump made clear Wednesday that he wants to not just enforce the immigration laws on the books but drastically change them, admitting fewer immigrants and making skills a higher priority in determining who is let in.

That is a major development in a debate that has largely been dominated by distinctions between legal and illegal immigration.

The bill sponsored by Sens. Tom Cotton, R-Ark., and David Perdue, R-Ga., that Trump endorsed at the White House goes beyond building the wall or dealing with illegal immigration. The RAISE Act would drastically reduce legal immigration and move away from a system where most immigrants are admitted because of who they are related to rather than what they can contribute to the U.S. economy.

"This policy has placed substantial pressure on American workers, taxpayers and community resources," Trump said. "Among those hit the hardest in recent years have been immigrants and, very importantly, minority workers competing for jobs against brand-new arrivals. And it has not been fair to our people, to our citizens, to our workers."

One reporter at the White House press briefing pointed to a seeming contradiction in how the bill was being sold, saying that Cotton and Perdue described it as "modest and incremental" while senior policy adviser Stephen Miller made "it sound so enormously important."

Miller, one of the leading voices for immigration restriction in the White House, repeatedly called the bill "historic," and his presence at the podium signaled at least some in the administration think it is important.

It is, to paraphrase former Vice President Joe Biden, a big deal. Where exactly Trump stood on legal immigration was an unanswered question from the campaign. In some of his speeches and in the plan on his website, Trump often supported reductions in immigration, but in off-the-cuff remarks he sometimes sent different signals.

Trump called for immigration reforms along the lines of what Cotton and Perdue are proposing as recently as in his February speech to a joint session of Congress. "Switching away from this current system of lower-skilled immigration, and instead adopting a merit-based system, we will have so many more benefits," he said. "It will save countless dollars, raise workers' wages, and help struggling families — including immigrant families — enter the middle class."

But then there was no legislation on this front from the White House, perhaps because congressional Republicans were already biting off more than they could chew on healthcare.

Since Trump occasionally contradicted his formal immigration policy pronouncements in unscripted moments — see his Republican primary debate with Sen. Marco Rubio, R-Fla., on the question of H-1B visas — it was always a possibility that they were more a reflection of his more immigration-obsessed advisers' preferences than the president's own.

Now Trump has attached his name to a bill that junks what had been the elite Republican approach to immigration reform from former President George W. Bush to the 2013 "Gang of Eight" bill. All those efforts increased legal immigration, sometimes substantially, while offering legal status to most of the illegal immigrants already in the country.

This bill is also the first serious attempt to reduce legal immigration since Congress voted on (and defeated) the recommendations of the Jordan Commission. And, as Miller acknowledged in his remarks at the daily briefing, it is a major departure from the family reunification-based immigration policy that has been in place since 1965.

Politically, this puts Trump unambiguously on one side of a debate that divides the Republican Party. House Speaker Paul Ryan, R-Wis., might follow Trump's lead on border security and the wall. The speaker isn't going to support cutting legal immigration in half.

Many Republicans would like to see immigration become more market-driven. That may make them open to a skills-based point system, but not reductions in the overall numbers. These GOP lawmakers tend to believe the existing caps are already too low, thus driving illegal immigration.

But there has been a significant faction of Republican lawmakers committed to lower immigration levels since at least the 1990s, led first by then Congressman Tom Tancredo, R-Colo., then-Alabama Republican Sen. Jeff Sessions, now the attorney general of the United States, and finally Cotton.

Many hardline Trump supporters hope this will signal a break with the priorities of Republican congressional leaders and a focus on the more distinctly populist platform the president campaigned on last year.

Serious questions remain, however. Does Trump's support, coming right before recess at what looks like the nadir of his influence on Capitol Hill, really move the needle for the RAISE Act in Congress? Could something like the RAISE Act get 35 votes in the Senate?

The Jordan Commission experience is instructive. A Republican-controlled Congress rejected a more modest attempt to reduce immigration in the 1990s because business groups convinced economic conservatives the idea was anti-free-market and influential social conservatives were persuaded that de-emphasizing family reunification was anti-family.

How committed is Trump to this kind of legislation? His remarks in support of it were more scripted and less effusive than Stephen Miller's. Once the president went off script, he began talking about the stock market.

The questions Miller faced at the briefing illustrate how hostile the press will be on this issue, especially the exchange with CNN's Jim Acosta over the Statue of Liberty.

There are organized interest groups that will mobilize against a bill lowering immigration levels. Nothing comparable exists on the other side of the issue. Labor unions largely abandoned immigration restrictionism in favor of Democratic coalition politics decades ago.

Public opinion polls have shown strong support for keeping immigration levels the same or cutting them, even as at least the last five presidents of both parties have wanted to increase them. But will voters support cuts of this magnitude?

Maybe they will if they respond favorably to the argument that immigration policy should be made primarily for the benefit of those already living in the United States. That argument seems to have already won over one American — the one currently residing in the White House.