The rivalry between Ted Cruz and Marco Rubio escalated over the weekend.

The field upon which both presidential candidates will fight one another for claim to primacy within the Republican Party’s “insider” lane appears for now to be the rather modest disagreements on the issue of immigration. Chief among those distinctions was at one point whether a comprehensive reform bill would be implemented simultaneously or whether it would be phased with border security provisions instituted either before or after the legalization of the nation’s illegal immigrant population. Ted Cruz has since disavowed his previous support for the legalization of the 11 million plus undocumented migrants in the United States, but only after he spent nearly a week clarifying his intentionally vague position on the matter. Perhaps in acknowledgement of that ancient political maxim — when you’re explaining, you’re losing – Cruz launched an offensive broadside against Rubio over the immigration issue. His is a line of attack so audacious that it may shake up the race.

The pundit class has long anticipated that Rubio’s authorship of and support for the failed 2013 Gang of Eight immigration reform bill would be his biggest liability in the race for the GOP nomination, and it may yet be. Cruz inadvertently dealt that thesis a blow, however, when his campaign released an advertisement attacking Rubio not explicitly on immigration but on terrorism. Over images of Syrian refuges and Islamic State terrorists flying their black flag atop a speeding tank, Cruz attempted to link immigration reform to national security. “Their misguided [Gang of Eight immigration] plan would have given President Obama the authority to admit Syrian refugees, including ISIS terrorists,” Cruz said. “That’s just wrong.”

Cruz is correct; that is “just wrong,” as in hopelessly factually inaccurate.

“Actually, this statement is simply bizarre,” wrote the Washington Post’s Glenn Kessler. “With or without the Senate immigration bill, Obama had the authority to admit refugees, from any country, under the Refugee Act of 1980, as long as they are refugees and are admissible. Every president since the passage of the law — Ronald Reagan, George H.W. Bush, Bill Clinton, George W. Bush and Obama — has exercised that right repeatedly for hundreds of thousands of refugees.”

“What does ISIS have to do with it? Nothing,” Kessler concluded.

So is Cruz’s tactical approach here merely to flail wildly at his target and hope to land a blow while incurring the wrath of the fact-checkers (Kessler awarded Cruz his worst rating, denoting blatant and premeditated mendacity for this ad)? Hardly. Ted Cruz’s strategy is as cold-eyed as it is ethically dubious.

Issues polls have long noted voters contend the issue of immigration ranks well below other priorities, including the state of the economy, the unemployment rate, the threat of terrorism, and health care. The vast majority of general election voters are not overly concerned with immigration, and there is little evidence to suggest that even a substantial number of Republican voters rank immigration as their chief priority for the federal government action.

The Wall Street Journal put immigration concerns in perspective for conservatives in an analysis of December’s NBC News/Journal survey. “According to the WSJ/NBC poll, 40% of respondents picked national security and terrorism as their top choice for government action. Job creation and economic growth came in second, with 23% respondents picking it as their top choice,” the report read. “Government spending and healthcare followed next, with only immigration and religious/moral values ranking below climate change (Emphasis added).”

By attempting to link Rubio not only to unfettered illegal immigration but terrorism, Cruz is throwing a Hail Mary that might alienate as many conservative voters as it energizes. So, with immigration ranking so low on voters’ list of priorities, why would Cruz put his credibility on the line with such a risky play? The answer is in the Journal’s reporting. The far-left partisans who defend their obsession with climate change do so by contending that it is the root cause for all of society’s ills. To seek to address terrorism, economic growth, joblessness, or even health care without an eye toward how all are affected by climatological concerns both domestically and overseas is merely combating the symptoms of a fatal disease.

There are conservatives who inhabit the event horizon around this same logical black hole. Illegal immigration is the central problem from which all other evils spring, some contend. Health care spending and access is a problem, the jobless rate continues to be vexing, the economic recovery is struggling, and terrorism threats are proliferating, but none of these matters can be effectively addressed without finally resolving the issue of illegal immigration and security along the southern border. For the most devout, immigration or climate change represent the theory of everything. It’s blindingly partisan and deeply self-deceptive, but this is nevertheless a widespread ailment among partisans on the farthest ends of their respective ideological spectra.

Which brings us back to Cruz. The intent of this full-scale atomic attack on Rubio was not to land a blow in the mainstream press. Indeed, Cruz knew he would only annoy reporters who concern themselves with factual accuracy by mounting this assault on Rubio’s record. His hope was to appeal to the conservative border hawk’s amygdala by linking border security with national security refugee resettlement with terrorism.

Negative ads work, and Rubio’s campaign has not answered his most caustic critics with the same kind of criticism meted out against him. For Cruz, his factually challenged attack on Rubio may succeed in the short-term. If it does, however, he suffers from the same problem that Hillary Clinton now faces in the general election. For Clinton, it is more pleasant to indulge the fiction that ISIS recruits terrorists by showing them pictures of Guantanamo Bay and Donald Trump than to address the fact that exporting terrorism and holding territory in the Middle East is what swells the Islamic State’s ranks. For Cruz, contending that border security is tantamount to national security might satisfy an audience of conservatives who prefer the narrow field of vision offered by their partisan blinders, but a general electorate will find this line of argumentation deeply flawed and unsatisfactory.