With thousands of illegal immigrant minors continuing to pour over America’s southern border, the same politicians are singing the same songs: we can’t close the border, we must pursue comprehensive immigration reform, we can only reach political consensus if we compromise on border enforcement. It’s all nonsense. As I’ve explained in this space, we could easily close the border if we had the political will to do so.

The lack of political will springs from a fundamental misunderstanding of the risks of mass illegal immigration – to immigrants, both legal and illegal, and to American citizens. Here, then, are the top reasons to close the border, and to close it forthwith:

Disease. America is now coping with diseases it believed it had eradicated, at least in part thanks to unrestricted immigration. In early June, ABC 15 in Arizona reported, “US Border Patrol agents are worried that what’s coming over into the US could harm everyone… Agents are worried about a viral outbreak.” According to Border Patrol Agent and Rio Grande Valley Union representative Chris Cabrera, agents are experiencing contagious outbreaks – and so-called quarantine areas are nothing of the sort, often separated from the general population by mere caution tape. “There’s been an outbreak of scabies that’s been going on for the past month,” Cabrera said. And it’s not just scabies, it’s chicken pox, MRSA, staph infections. The Department of Homeland Security will not allow media to speak with doctors and medical staff treating illegal immigrants. A health official told The Blaze, “There is really no hard stop at the border, and we have no idea health-wise what diseases are coming across.”

The Safety of US Citizens. Crafting a system in which American authorities have no idea who is in the country is a recipe for public safety disaster. Immigration and Customs Enforcement admits that in 2013, it released 36,007 convicted criminal aliens awaiting deportation outcomes, including immigrants responsible for homicides, sexual assaults, kidnapping, and other serious crimes. The CIS breaks it down: “193 homicide convictions (including one willful killing of a public official with gun); 426 sexual assault convictions; 303 kidnapping convictions; 1,075 aggravated assault convictions; 1,160 stolen vehicle convictions; 9,187 dangerous drug convictions; 16,070 drunk or drugged driving convictions; 303 flight escape convictions.” Meanwhile, ranchers along the southern border are victimized with impunity by drug cartels exploiting the open border.

The Safety of Illegal Immigrant Children. This new influx of illegal immigrant minors is unprecedented. Thousands of children, some as young as four years old, have been found crossing the border. Some have been found dead. Children are sometimes used by Mexican drug cartels, as well. While the Obama administration loudly proclaims that it doesn’t want children being sent through Mexico to the United States, they refuse to state that illegal immigrant minors will be deported. Homeland Security Secretary Jeh Johnson refused no less than six times on Sunday to say as much. Meanwhile, the Obama administration has already stated that it will not deport so-called DREAMers, illegal immigrants without felony records between the ages of 16 and 30.

The Threat of Terrorism. Both of our borders, northern and southern, are a source of anxiety with regard to terror. In 2011, a report from the Senate Homeland Security Committee found that the Canadian border gives “easy passage into America by extremists, terrorists and criminals whose purpose clearly is to harm the American people.” This month, Marine Corps General John Kelly, commander of US Southern Command, said that the southern border had become a “crime-terror convergence.” He explained, “All this corruption and violence is directly or indirectly due to the insatiable U.S. demand for drugs, particularly cocaine, heroin and now methamphetamines, all of which are produced in Latin America and smuggled into the U.S. along an incredibly efficient network along which anything — hundreds of tons of drugs, people, terrorists, potentially weapons of mass destruction or children — can travel, so long as they can pay the fare.”

Low-Wage US Workers Will Pay. Unions largely support illegal immigration, for three reasons: (1) they hope that illegal immigrants will one day vote, and vote for their political allies; (2) they understand that more illegal immigration means broader government, and government workers are more heavily unionized than private sector workers; and (3) they hope to legalize those illegal immigrants to force them into unions. Nonetheless, it is low-wage workers in the United States who pay the price for illegal immigration. According to the Center for Immigration Studies, virtually all of the net gain in jobs between 2000 and 2013 went to immigrants, either legal or illegal. Immigrants particularly made major strides in “building cleaning and maintenance and construction and extraction.”

The Taxpayers Will Pay. The illegal immigrants crossing America’s southern border are not villains. Most of them are likely looking for a place to work. But that doesn’t mean they’re not draws on public resources. Illegal immigrants have a poverty rate of 26 percent, twice that of the native-born. In Texas, CIS says that 58 percent of illegal households are on some form of welfare; that’s 55 percent in California. Taxpayers spend approximately $40 billion per year on education for illegal immigrants or their children. A huge majority of illegal immigrants don’t have health insurance, which means they take advantage of public services in some form or fashion. This isn’t about the intent of illegal immigrants, which may be great – they may be here to work, to contribute, to build a better life. But adding a huge pool of unskilled immigrants without legal working papers sets up a drain on the public dime.

Voter Fraud. The left dismisses the possibility of voter fraud while simultaneously declaring that voter ID is racist. But today’s decision from an Arizona court mandating that drivers’ licenses be distributed to illegal immigrants who will not be deported by the Obama administration puts us firmly on the road toward serious voter fraud.

American Culture Is Under Attack. This is not the fault of immigrants to America, who, like all previous generations of immigrants from a myriad of other countries (including my great-grandparents from Eastern Europe), would be willing to acculturate to the United States. This is the fault of the left, which has suggested that the melting pot ideal with unique American values is culturally imperialistic and patriarchal. The result is an increasingly fragmented nation.

Despite these grave threats to America, members of both parties continue to pretend that leaving the border open is a viable option – Republicans, because they are beholden to big businesses seeking cheap labor, and Democrats, because they wish to confiscate the wealth of citizens. But at this point, there is simply no excuse for not closing the border.

Ben Shapiro is Senior Editor-At-Large of Breitbart News and author of the new book, The People vs. Barack Obama: The Criminal Case Against The Obama Administration (Threshold Editions, June 10, 2014). He is also Editor-in-Chief ofTruthRevolt.org. Follow Ben Shapiro on Twitter @benshapiro.