Republican presidential candidate Ted Cruz gets off his bus at King's Christian Bookstore in Boone, Iowa, on Monday. (Aaron P. Bernstein/Getty Images)

WEBSTER CITY, Iowa — Sen. Ted Cruz (R-Tex.) began laughing as soon as the question started.

Last night — after his last press availability of the day — Sen. John McCain (R-Ariz.) told a Phoenix radio host that questions about Canada-born Cruz's eligibility for office were "worth looking into." In an interview with Bloomberg Politics today, Cruz said McCain reacted that way because he is "supporting Marco Rubio in this election"

Shortly before 4 p.m. here, the assembled media outlets got their chance to follow up. "Senator McCain is questioning, legally, whether you can become president," ABC News's Tom Llamas asked. "Do you have a problem?"

Hence the laughter. "Oh, listen," Cruz said, "Everybody knows that John McCain is going to endorse Marco Rubio. Their foreign policies are almost identical. Their immigration policies are identical. So it's no surprise that people who are supporting other candidates are going to jump on the silly attacks that come as we get closer and closer to this election."

Cruz got three more questions, one about Texans working for him in Iowa and two essentially about front-runner Donald Trump and McCain. Cruz deftly turned each answer into a page of his campaign stump speech. That's what many candidates try to do — usually with less art — but Cruz may be unique. So far, given the lack of damage from the Canada story to his image among conservatives, Cruz actually benefits from Trump's full-spectrum dominance of the national media conversation.

Cruz does this by blaming every incoming attack on two factors. The first is his strength in the polls; Cruz will suggest that "three weeks ago, every Republican was talking about Donald Trump." Not so much now, in his view. The second is the mainstream media, one of the softest targets in Republican politics. (Cruz's stump speech, which changes subtly from stop to stop, always includes a joke about reporters "checking themselves into therapy" after his hypothetical presidency ends in 2025.)

In Webster City, Cruz used most of his news conference to gently chide the media, saying they are not asking about anything Iowans seemed to be interested in. When CNN's Dana Bash asked whether Cruz would take Trump's advice and embark on a legal route to prove his eligibility to be president, he took another chance to ask why no one was covering the proverbial Real Issues.

"I'm not going to be taking legal advice from Donald Trump," Cruz said. "My response when Donald tossed this attack out there was to tweet a video of the Fonz jumping the shark in 'Happy Days.' These attacks — this is the silly season."

"He has 5½ million Twitter followers," Bash said.

"At the end of the day, what the voters care about is who's prepared to lead this country," Cruz said.

After one more question about whether establishment Republicans such as McCain were feeling more confident in attacking him, Cruz started his town hall. Something obscured by the endless Trump news cycles was suddenly much clearer: Cruz was the most conservative candidate in the race and ready to indulge questions that other Republicans dismissed.

One questioner asked about the alleged influence of the Trilateral Commission and David Rockefeller, two bugbears of conspiracy theorists. "It's a very good question," said Cruz, pivoting to discuss the Medellin national sovereignty case, which is featured in some of his TV ads here. Another questioner asked whether the Federal Reserve was constitutional, prompting a short monologue by Cruz about why America should return to the gold standard.

And another questioner asked about the potential threat of Muslim courts issuing their own sharia-based rulings within the United States.

"Under no circumstances should sharia law be enforced anywhere in this country," Cruz said. "We should do whatever it takes to prevent that."

Without Trump in the race, questions and issues such as these — the sort of things that have stymied some tea party candidates for lower offices — might be controversial. But Trump, who has courted controversy again and again in the past few months, is in the race.