The left wing in the West and in the US is built upon revolution and subversion. The only way that the modern Western/US left, which has views at odds with all of human history, and with what is necessary for a nation to function and grow, to become not just the dominant, but axiomatic position, is through a decades long process of taking and subverting the institutions, and once the institutions are captured, subtly, but unceasingly reinforce these views so as to make any ideology besides it seem to be radical and dangerous. 

Combined with that is the usage of institutional and informational control to straw man any opposing ideology, and force that opposing ideology to explain itself on the left’s terms.

They also use motte and bailey tactics on their ideological opponents (in this case Trump) where they first claim the other side is an existential danger, and when challenged, retreat to a more mild criticism that they claim was what they meant all along.

On immigration, first it is that the opposition to illegal immigration and deportations, and rhetoric around it, are fascist. Then when presented with facts that Democrats in the 1990s and 2000s said essentially the same thing, and Obama deported more illegals than any President, retreat to saying that the “manner” in which Trump says things, or the “manner” in which ICE operates is the problem.

But of course, if not challenged and refuted on their original point, they have continued to claim it. The same thing goes for BLM, Defund the police, the 1619 project, LGBT issues etc. 

Also part of the subversion is, through control of media and institutions, forcing the left wing’s opposition to defend their most extreme element, and the presenting of that most extreme element as the standard bearer for the movement.

In the case of Trump especially, the left uses their control of purveyors of information to bog down progress and the ideological debate in discussions about Trump’s schizophrenic actions as a way to create a sense of extremism and chaos associated to the left’s opponents, when the fundamental direction and message of the left’s opponents are logical, moderate, and in a broad sense, much more popular with the populace than the left’s ideology.

The left has been able to do this because they have had a slow, methodical takeover of the institutions over decades, which they then use to slowly and methodically insert their ideology as default axioms.

From there on out, any conservative worldview is not only described as extreme and controversial, but must be explained against the default of leftism. This has always made the conservative position seem more extreme, when it is the more moderate, default position.

As long as this fact remains unchallenged, while conservatives can gain victories, they will always be fighting an uphill battle, and it will be difficult for them to gain comprehensive, long term, sustainable victories.