The Boston bombing crime shows that comprehensive immigration reform should not be only a southern border problem or even just a problem of illegal aliens. It’s also a problem of foreigners who are admitted legally but should never have been admitted, and of others admitted legally on a visa but are not tracked to make sure they depart when their visitor’s time expires, as U.S. law requires.For starters, why would our government have admitted the Tsarnaev family whose son was named Tamerlan? That should have been a red alert because that is the name of one of the world’s notorious mass murderers, a 14th-century Central Asian warlord named Tamerlan, who killed about 17 million people.The original Tamerlan was a devout Muslim who referred to himself as the Sword of Islam and was especially known for his shocking brutality. His name is well known in Central Asia.Senator Chuck Grassley (R-IA) said that the Boston bombers’ crime poses questions similar to those we asked after the 9/11 terrorist attacks on the World Trade Center in 2001, such as “How did 19 people get in here to kill 3,000 people?” He said the Boston marathon crime is “a reminder that we’ve got to do better than what we’ve done. They were evidently here legally.”Grassley said the Boston crime should trigger the U.S. “to understand the gaps and loopholes in our immigration system.” He asked, “How do we ensure that people who wish to do us harm are not eligible for benefits under the immigration laws, including this new bill before us?”The leftwing politicians and media outlets are disappointed with the outcome of the investigation into the Boston bombing. They can’t blame it on lack of gun control, the NRA, the tea parties, right-wing extremists, or budget cutbacks required by sequestration.Salon columnist David Sirota wrote, “Let’s hope the Boston Marathon bomber is a white American.” What he may have meant, of course, is that he hoped the bomber would be a mainstream Christian American so the atrocity could be blamed on the American culture.What worries America-hating liberals and progressives is that we will wake up to the fact that our government is now importing refugees, Muslims, polygamists, and other difficult-to-assimilate foreigners in unprecedented numbers. From a distance, rebels in Chechnya, Syria and Egypt might seem like freedom fighters, but they may be terrorists who have no desire to be American.It’s long overdue for Congress to have a series of hearings on the loopholes, broken promises, and disobeyed laws involving both legal and illegal entry into the United States. It would be useful to reinstate the House Committee on Un-American Activities so we can have a look at those in our midst who may be jihadists, or dupes of violent Muslim indoctrination, or (in old Communist lingo) fellow travelers or useful idiots.We need hearings to find out why the Tsarnaev family was not thoroughly vetted before it was admitted to our country, or even after Russia tipped off our FBI that Tamerlan could be a dangerous risk, or especially before Tamerlan was re-admitted to the U.S. after his trip to Russia in 2012. Russia told the FBI that Tamerlan “was a follower of radical Islam and a strong believer, and that he had changed drastically since 2010 as he prepared to leave the United States for travel to the country’s region to join unspecified underground groups.”Dealing with the widespread fraud in our easy acceptance of refugees should also be part of comprehensive immigration reform. After all, the Tsarnaev family came into our country as refugees.The vetting of immigrants should make sure that the applicant really wants to become an American. The immigrants of earlier generations, Irish, Italian, Jewish, etc., certainly did want to be Americans; like Irving Berlin, their attitude was God Bless America.There is plenty of evidence that legal and illegal immigrants of various nationalities, in contravention of our citizenship pledge, retain their loyalty to the land they came from. Brian Fishman, who studies terrorism at the New America Foundation in Washington, says, “I think there’s often a sense of divided loyalties in these cases where Americans turn to violent jihad — are you American first or are you Muslim first?”Our government should investigate thoroughly and reject those who do not want to become Americans, obey our Constitution and laws, speak our language, and salute our Flag. And they have to accept the rule that disputes in our courts must be decided according to U.S. law, not any foreign law.