> vilifying political opponents (the ones that believe in some kind of immigration control and do not support fully open borders)
The only vilification happening here is your misrepresentation of the critics of ICE, many of whom do not advocate for "open borders".
ICE is not equivalent to "border security", which should be obvious when you consider that this agency was only created in 2002.
ICE doesn't even work at the border. That's the Border Patrol (and customs, and the Coast Guard).
ICE exclusively works within the US. Since illegal immigrants have little protection, it acts much like any unchecked police force, at least according to its critics.
There were 1,200 complaints of sexual assault in ICE custody[0], for example. Less than 2% of these were investigated[1], proving the point about them acting "largely unchecked" that I somehow felt the need to qualify with "according to its critics", above, before looking this up.
From 2012 to early 2018, ICE wrongfully arrested and detained 1,488 U.S. citizens, including many who spent months or years in immigration detention.[2]
Since it isn't particularly hard to find illegal immigrants in the US, ICE also has a lot of liberty to decide who to go after. That's a recipe for arbitrary enforcement, and there have been complaints about individuals, families, neighbourhoods, or cities being targeted or a variety of reasons, none of which fit most people's idea of justice, from shakedown collecting money from individuals in exchange for sparing them harassment to cities being targeted after incurring the wrath of the current government.
[0]: https://theintercept.com/2018/04/11/immigration-detention-se...
[1]: https://en.wikipedia.org/wiki/U.S._Immigration_and_Customs_E...
[2]: https://en.wikipedia.org/wiki/U.S._Immigration_and_Customs_E...