The horrific death of a California mom by an illegal immigrant deported five times is unfortunately proof of outspoken GOP presidential candidate Donald Trump's warning about undocumented workers, according to a leading immigration watchdog group.

In a new blog post decrying the lack of comment by presidential candidates on the slaying of Kathryn Steinle, shot on San Francisco's Pier 14 last week by a migrant, Mark Krikorian, executive director of the Center for Immigration Studies, expressed shock that the same GOP candidates who have decried the Confederate flag have been silent.

"Even the Republicans haven't jumped on this — other than Trump, whose widely mocked warnings of this very danger have been vindicated. This was the perfect opportunity for Walker or Rubio or Cruz (Jeb is hopeless, of course) to steal some of Trump's thunder by offering a sober but scathing critique of the Obama-Clinton policy of dismantling our immigration-enforcement infrastructure — but so far it's crickets," he blogged.

"And this despite the fact that deporting illegal-alien criminals is probably a 95 percent issue among Republican primary voters and a 75 percent issue among voters in general," he added.

Donald Trump. AP Photo

Since making controversial remarks about Mexican immigrants in declaring his presidency, Trump hasn't backed down despite an outcry from Latin America.

Saturday on Fox, for example, he said the San Francisco case is "another example of why we must secure our border immediately."

He has also made the slaying a political issue within the GOP primaries, accusing former Florida Gov. Jeb Bush and Texas Gov. Rick Perry of being weak on the issue.

Paul Bedard, the Washington Examiner's "Washington Secrets" columnist, can be contacted at pbedard@washingtonexaminer.com.