If ICE were rounding up Democrats now (or Republicans under Obama) that would be "political enemies". ICE is doing no such thing. Part of its mission is enforcing US immigration laws, and it's doing that in a manner that's largely consistent with what our democratically enacted laws say it can and should do. You don't have to like it (I certainly don't) but it's not in any way analogous to the Gestapo.

Whether or not their actions are consistent with our laws, and whether or not they are similar to the gestapo is orthogonal to the morality of their actions, and the morality of knowingly dealing with them. That's the real question to be asked.

I think there is a distinction between illegal immigrants (people who are not in the country legally as citizens or on a visa, regardless of country of origin) and asylum seekers. One has support of legislation (asylum seekers), the other does not (without disregarding the idea of national sovereignty; this thread should not be where the merits of borders and sovereignty is debated though). Regardless, everyone in ICE custody should be treated humanely and with dignity.

That's why I'm making the quote "illegal aliens". The majority of people who are in ICE custody are, as far as I understand, legal asylum seekers. However, they're depicted as illegal.

https://www.ice.gov/detention-management#tab2 appears to be a canonical statistics data source, although I admit it will take me more than a cursory glance to have an understanding of the data, and I don't want to make a statement that isn't accurate due to not having a full understanding of said data.