Democrats like illegal immigrats. They tick several boxes on things that make Democrats like them:
Democratic administrations deport some people caught at or near the border, but once the illegals have made it some distance into the country, found a place to live, and gotten a job, Democrats are deeply morally opposed to removing them. They just think it's mean.
Our borders are long and porous, and many illegals come in with legal visas and overstay. Thus, it is impossible to enforce the borders without removing settled residents, and millions of them.
So far, Trump has not succeeded in deporting very many people -- about 400,000 according to the Associated Press, about 700,000 according to DHS (which is not credible), and about 400,000 self-deportations (2.2 million according to DHS, again not credible), compared to an estimated 4-6 million people who got in and stayed in under Biden.
So the status quo is that Democratic administrations will let illegals in much faster than Republican administrations can kick them out.
In 1986, Reagan did an amnesty giving most illegal aliens a path to citizenship. Part of the deal was that there would be increased border enforcement after that. The increased border enforcement failed to materialize, and the amnesty drew in millions more illegals in the hope of a future amnesty for them. To add insult to injury, most of the naturalized illegals, once they began voting, voted solidly Democratic. The Republicans have learned their lesson from this -- they will engage in no talk of a "path to citizenship" for illegals until the country demonstrates an ability to control its borders across both Republican and Democratic administrations.
At least 50% of our economic debate revolves around a single issue: Low-skilled labor is so over-abundant that low-skilled people can't negotiate the sort of pay and working conditions that we would like everybody in our society to have.
There are a few popular solutions to this:
50 years ago, there were many well-paying low-skilled union manufacturing jobs in the US, but with globalization, free trade, and the development of the third-world, many of those jobs went offshore, leaving rotting, deserted cities in the US. There were some local low-skilled jobs that couldn't be offshored, but what wound up happening is that third-worlders flooded into the country to fill them.
There are some so-called "studies" that claim that the impact of illegal immigration on low-skilled wages is pretty minimal, which goes to show that you can rig a "study" to come to any conclusion you want. Basic common sense and the slightest grasp of the law of supply and demand tell us that that the illegal influx of millions and millions of low-skilled people is guaranteed to have a major negative impact on the bargaining position of low-skilled American citizens.
Both globalization and the failure to enforce the border were shafting the economic interests of Americans who didn't go to college, and for many years, the government didn't care. Eventually these shafted people rebelled and elected Trump.
Democrats are morally incapable of having an intelligent conversation about strengths and weaknesses of cultures, which creates an enormous blind spot in their world view. According to the liberal mindset, if a demographic or nation is experiencing any unfortunate outcome, it is never the fault of their own culture, it is always because they have been somehow supposedly "oppressed" by some more supposedly "privileged" group. This is usually wildly at odds with reality.
As a computer programmer, most of my co-workers throughout my over 40-year career have been immigrants, and that includes a lot of immigrants from third-world countries. An immigrant from one country told me how she could drive like a maniac back home, and if a cop pulled her over, she'd just pay him a bribe, equal to about two US dollars, and he'd let her go. Another time I took a cab in another third-world country and the 20-year-old driver would sail through red lights crossing busy 4-lane roads at full speed -- he did that through every red light we encountered crossing a big city. Obviously what was happening was that any time a cop pulled him over, he'd pay off the cop as a cost of doing business and go on his merry way. He was going to keep doing that all day every day until he killed somebody.
I've seen a country where the cops were so corrupt and incompetent at catching crooks that every single store with a cash register had a privately hired armed security guard standing on the sidewalk. Downtown, you'd see these guards lining the sidewalk, at least one in front of every store. A MacDonald's would have several.
The nature of cultural advantages that countries people move to have over countries people move from is not widely discussed in the liberal media because liberals find the topic so distasteful. Here are a few:
The reason people want to migrate to the US from other countries is that this is a better place to live. The reason it's a better place to live is that we have cultural advantages over the immigrants' countries of origin. It is important to preserve these advantages, which will be impossible unless we can exercise enough control over the flow of people coming in that the population of newcomers can be kept small enough to be assimilated.
The percentage of American residents who are foreign born is the highest its been since at least 1850.
When deportation raids in LA caused rioting and Trump sent in the National Guard to defend ICE, the Democratic mayor of LA did not make a credible promise that the LAPD would defend ICE and enable them to do their jobs, making the National Guard unnecessary -- she just demanded that deportations cease. Similarly, when Minneapolis erupted in resistance to ICE activities, local and state Democratic leaders as well as many citizens in the streets, demanded an end to all deportations rather than a modification of tactics. Many Democrats across the nation are chanting "ABOLISH ICE" which basically means a complete end to all hope of effective border enforcement. Democratic demands for DHS funding by federal congress include "No ICE searches without a judicial warrant." which is unreasonable -- there is nothing unconstitutional about searches without warrants, cops do it all the time based on something called "probable cause". It is clear that the intention of the Democrats in congress is to gum up the works with red tape to make it as difficult as possible for deportations to happen.
The approach to border enforcement in Trump's second term has been botched -- characteristically divisive, brutal, spectacular, and polarizing, with under-trained masked agents being abusive and often crossing legal boundaries. In addition, when agents mess up and kill people, the administration's response has been to flagrantly lie about it in a manner obvious to anyone watching the videos.
A big part of the Trump border enforcement strategy was to be as spectacularly brutal as possible and just terrify the illegals into self-deporting. The tactic of sending a bunch of tattooed Hispanics (not clear whether there was a single gang tattoo on any of them) to a third-world hell-hole of a prison without due process was obviously intended to scare Latino gang-bangers in the US into self-deporting. All this grisly spectacle probably motivated some self-deportations, and deterred others from immigrating, but it provoked a Democratic backlash against all border enforcement.
Trump and the right-wing media never made much of an intelligent case that border enforcement was necessary or important. They went on about them all being horrible criminals, but illegal immigrants are statistically very law-abiding since they're on best behavior fearing deportation, it's just that their American-born kids are another story, and their kids can't be deported. But it's hard for one party to enforce the border when the other party is trying to undermine the effort any way they can. Trump is inherently incapable of persuading Democrats of anything, lacking a single bipartisan bone in his body.
The Republicans should employ a different, less dramatic, but more effective, approach -- go after employers. There are already stiff fines in federal law for businesses that employ illegal aliens, with stiffer fines for repeat offenders. DHS should do raids on workplaces, going in with video cameras photographing all employees. The employer then has a few days to cough up paperwork showing that the employees have a legal right to work in this country, if not, fines are levied. Raids are followed up with repeat raids a few weeks later, if the illegals are still there, stiffer fines are imposed.
This should raise plenty of revenue until the raids succeed in deterring businesses from hiring illegals. Once the illegals can't work, they will self-deport, quietly, families intact. There will be no viral videos of ICE shooting anyone, no need to detain anybody in the Alligator Alcatraz, no need to fund or expand our expensive and overburdened immigration courts, the cost of the court burden to impose the fines on employers can easily be offset by the revenue of the fines.
This way, the Republicans could cheaply and effectively remove millions of illegals from the country during a single presidential adminstration and undo all the illegal border crossings that occurred during the interceding "wide open door" Democratic administrations.
Once this is done, we will have effective border control across Republican and Democratic administrations. Then, and only then, can we start to discuss how many illegals we will allow to stay and pursue a path to citizenship.