It's estimated that illegal immigrants cost local and federal governments $50-$100 billion in all services provided: health, education, welfare, food stamps, etc. To give you an idea of what that represents, the total US Department of Education budget is $70 billion. The point is illegals cost a substantial amount. Also, the local costs are not spread around equally. Illegals tend to congregate in certain areas so their burden for local governments and taxpayers in those areas can be substantial especially since the illegals don't contribute that much in taxes to offset their costs. So Americans like me have to pay higher property and state taxes for illegals.
Of course, my higher taxes may be offset by cheaper gardeners who tend to be Mexican and central Americans. Don't know how many are illegals. Also, they make up a big part of restaurant cooks and service people there, and there are some good Mexican restaurants where I live. So on balance, I personally might not have much to complain about. 
Let's assume that estimate is correct and not fake news, it's still only half the story. Presumably, these people are working at something somewhere, so they contribute to the economy. If your argument is that because they're illegal then they don't pay taxes, i.e., don't pay into that social safety net out of which they draw benefit, then how is that any worse than Trump not paying any tax (assuming his bragging about not doing so is true). If they are living and working in your cities, then they are contributing to the economy by buying food, clothes, cars, paying rent, etc. The consumption of those goods and services IS the economy.
People expend an inordinate amount of emotional energy, it seems to me, worrying about the possible "costs" that illegals cost the system, but are there data showing that they cost the system any more than legal citizens do? How does that compare to the various forms of corporate welfare that the various levels of government pay out to Big Oil, Big Corn, Big Sugar, etc.
How much tax money paid by the avg joe is turned over to the one-percenters who own pro sports franchises when cities and states given them stadiums and other tax holidays based on the confidence game that these places benefit local economies (something that has been fund untrue by every economic analysis ever done)? We like to make fun of corrupt governments in the underdeveloped world, but viewed from a couple of steps back, how is the handing over of tax money to pro sports enterprises anything but corruption? It's theft on a grand scale, imo, although at the same time I have to admire the audacity of the con.
