Nothing wrong with it at all, but Trump has indeed talked about 100 percent deportation, which, I imagine, qualifies as "mass." I don't know if he intends to do it all at once (if that is the proper definition of "mass") or through attrition however.
There is no political will for mass deportation. Rounding up 12 to 30 million illegals is a non-starter.
The proponents of amnesty are wont to create the false choice between a blanket amnesty and mass deportation of 12 to 30 million illegal aliens. In reality, we have other choices and alternatives that don’t reward people who have broken our laws with the right to stay and work here and an eventual path to citizenship. The 12 to 30 million illegal aliens did not enter this country overnight and they will not leave overnight. Attrition through enforcement works. We have empirical data from Georgia, Oklahoma, and Arizona proving that it does.
If you take all the steps I mentioned in a previous posting, you can drastically reduce the number of lawbreakers and future lawbreakers. I see no sense of urgency of trying to round up all the lawbreakers. We can start with the estimated 2 million criminal aliens. We have about 1 million convicted criminal aliens who have been released by the federal government. These absconders were ordered deported, but they never left.