Without ever leading in a single poll, Ted Cruz has become the frontrunner in Iowa.

The Texas senator and conservative firebrand has closed the gap on real-estate mogul Donald Trump and is now trailing Trump by only a margin of 25% to 23% in the Hawkeye State, according to a poll released on Tuesday by Quinnipiac University. But, more than that, Cruz has been notching up key endorsements in Iowa and positioning himself to win the state’s first-in-the-nation caucuses on 1 February.

The poll comes in the aftermath of Cruz’s successful appearance at the Presidential Family Forum in Des Moines last Friday, hosted by social conservative powerbroker Bob Vander Plaats. The event’s moderator, top Republican pollster Frank Luntz, told the Guardian that Cruz “had the biggest meeting after the session. He was the most organized, most professional, doing this all step by step.” Luntz said the Texas senator deserved superlatives for every aspect of his performance: “If there was a most, he had it.”

Steve Deace, a well-connected conservative radio host and Cruz supporter, echoed Luntz’s praise of Cruz’s performance at the event. But he noted that Cruz would have been in strong position regardless of how he had done at the event with “the existing organization and support he had built”.

To Deace, the one area where Cruz had been “a little bit soft” was in ardently conservative north-west Iowa. However, the Texas senator had addressed that weakness when he secured the endorsement of congressman Steve King earlier in the month, Deace said. King, a vocal opponent of illegal immigration, is wildly popular among Republicans in that part of the state and is considered to be the most influential conservative in the state.

But that doesn’t make Cruz inevitable yet.

Trump has built up a strong organization in the state and has more staffers on the ground there than any other Republican candidate. The real estate mogul has drawn unprecedented crowds at events across the state and, with the exception of a two-week hiccup during Ben Carson’s October surge in the state, has led in every poll since August.

Last week, King told reporters he would not rule out Trump winning on caucus night. He said: “If I had predicted Trump’s ascendance, I’d have more confidence in predicting his downfall.”

But for all of Trump’s staying power, his campaign seems to have reached a ceiling. Deace compared Trump to former Texas congressman Ron Paul in that both candidates had “a high floor and a low ceiling”. Deace thought Trump’s antics were “both a good and a bad thing”.

“On one hand, it produces a loyal following that is attracted to that persona which will not leave you. On the other hand, it limits your ability to grow beyond that,” he said.

This was borne out in Tuesday’s poll, in which Cruz did better than any other Republican when respondents were asked which candidates they would definitely not support for the GOP nomination. Only 5% of respondents ruled out backing Cruz while 26% said they would not back Trump. Cruz’s advantage is that, while he is by no means an insider, he has managed to become the strongest candidate among party activists in both the evangelical and Tea Party factions of his party.

The Texas senator’s campaign has now moved on to waging a quiet war with Rand Paul’s supporters over the small but influential libertarian wing of the GOP. While Paul has held on to almost all of the key activists in Iowa who supported his father in 2012, that support has not been reflected in his poll numbers. Cruz has waged a steady appeal to more socially conservative libertarians who have not embraced Rand Paul in the same way that they backed his father, Ron, and he is attracting Republican regulars from different wings of the party.

In contrast, Trump’s supporters are irregular voters at best. Many of the crowds at his rallies may just be there for the celebrity experience – after all, while politicians visit quite frequently, it’s not often that a television star comes to Burlington, Iowa. Even those most devoted to him have rarely participated in a caucus. The typical supporter is someone like Phil Burnsmann of Fairley, Iowa, who camped for hours in August to see Trump appear in Dubuque. He seemed befuddled when asked about the last time he had caucused. “When Bush was in there,” Burnsmann haltingly told the Guardian.

Steve Rosanke, of Dubuque, said at the time: “I haven’t been to a caucus for a while, that would be when I was in college, a few years back.” He added: “I always vote but I don’t always vote Republican.”

The key challenge for the Trump campaign is to somehow convert these supporters into caucusgoers and lure them out for hours on a cold February night.

For now, Cruz’s advantage is that he has a much easier task. His supporters will be showing up on caucus night no matter what. The Texas senator just has to make sure that they are staying in his corner.

Additional reporting by Mona Chalabi in New York