Donald Trump's immigration plan seems like a terrible idea

I know that some people like Donald Trump's immigration plan. However, I am having a difficult time understanding why. To me, it seems like a terrible idea. What am I missing?

I agree with this editorial, from Ruth Marcus at the Washington Post:

The false assumptions underlying Trump’s immigration plan

Marcus argues: "Donald Trump’s immigration proposal rests on three assumptions: that immigration hurts American workers; that illegal immigration, in particular, is linked to violent crime; and that illegal immigrants drain government resources. Each of these beliefs is belied by the available academic evidence."

Regarding Trump's first assumption, that "immigration hurts American workers," Marcus cites a policy memorandum from the Brookings Institution, which argues that "on average, immigrants raise the overall standard of living of American workers” because "immigrants and U.S.-born workers generally do not compete for the same jobs; instead many immigrants complement the work of U.S. employees and increase their productivity." Marcus acknowledges that "economists disagree most sharply over immigration’s impact on the wages of the small share of U.S.-born workers with less than a high school education," but she argues that there are "far more effective ways to tackle that problem than deporting illegal immigrants."

Regarding Trump's second assumption, that "illegal immigration ... is linked to violent crime," Marcus argues that "[s]tudy after study has debunked the notion that increased immigration, legal or illegal, produces a spike in crime."

Regarding Trump's third assumption, "that illegal immigrants drain government resources," Marcus acknowledges that "[i]mmigration does strain state and local budgets, particularly for education." But she argues that "for the federal budget, immigration represents a fiscal plus." "Illegal immigrants aren’t entitled to welfare, food stamps, Medicare or Social Security or unemployment benefits. ... [T]hey often pay federal taxes and contribute more than $12 billion annually to Social Security alone without being able to collect."

Here's another article about Trump's immigration plan:

Everything* Donald Trump’s Immigration Plan Gets Wrong

Regarding immigration and crime, this article argues:

“A recent report from the Immigration Policy Center found that immigrants as a whole have lower crime rates than the native-born population, while an earlier report from the same group found that Mexican and Central American immigrants — who make up the majority of undocumented residents — are also less likely than native citizens to be incarcerated for crimes. … Other researchers have raised questions about the Immigration Policy Center’s conclusions, pointing to potential irregularities in census and other data sources. But researchers generally agree that there is little evidence that immigrants, documented or undocumented, commit crimes at a higher rate than the native-born.”