Three weeks before Iowa kicks off the 2016 presidential campaign, Donald Trump and Ted Cruz are generating overwhelming enthusiasm among Republican voters in the state, along with concern, though not panic, among the party professionals who believe both are unelectable in November against the Democratic nominee.

Despite such fears, talk of a “takedown” effort aimed at either Trump or Cruz appears to have faded as the Feb. 1 caucuses in Iowa near. For now, there is nervous acceptance that two of the Republican Party’s most divisive figures may stay at the top of the presidential pack well into the first month of voters’ getting their say.

“Cruz would not only cost us the general, he would cost the GOP the future. Trump is not a Republican and he is not a conservative,” said Republican strategist Alex Castellanos, who is not affiliated with a 2016 campaign. “The geometry is conflicting: If you limit one, you aid the other.

“At the end,” Castellanos said, “Republicans may face the devil’s bargain and have to settle for the lesser of two anti-establishment evils.”

That feeling is echoed by party officials across the country, who acknowledged they have few tools to stop Cruz or Trump. Instead, there is hope that voters ultimately settle on what they consider a more viable alternative from a group of candidates that includes Florida Sen. Marco Rubio, New Jersey Gov. Chris Christie, former Florida Gov. Jeb Bush and Ohio Gov. John Kasich.

“Let’s see how the votes go before we panic,” said Washington-based Republican operative John Feehery, who has been critical of Cruz and Trump.

There is little evidence of widespread alarm from establishment Republican leaders and their well-funded supporters. Despite their commanding presence in preference polls, Trump and Cruz have almost completely escaped paid attacks, particularly in Iowa.

A Florida billionaire spent $40,000 on newspaper ads to hit at Trump in early December. One, in Iowa, called the political novice a “destroyer.” A group backing Kasich put $15,000 into an online anti-Trump attack in late November and early December, but there was no special focus on Iowa.

A nonprofit group led by a political operative who has endorsed Rubio spent about $200,000 to air an ad in Des Moines that knocked Cruz for his opposition to National Security Agency surveillance, saying the Texas senator “voted to weaken America’s ability to identify and hunt down terrorists.” But that ad has not been on the air in at least a month, according to Kantar Media’s CMAG political advertising tracker.

Republican National committeeman Ron Kaufman of Massachusetts said the party’s “centrist conservatives” will have to be patient until what they see as a more electable alternative to Trump and Cruz emerges.

“This is about who’s going to be in the finals,” Kaufman said. “Clearly on one side it’s going to be Trump and/or Cruz. And for the centrist conservatives, it’s going to come down to one of three governors or Rubio.”

That may explain why the attacks on Cruz and Trump pale in comparison to the amount spent disparaging other candidates. For example, a Rubio-boosting group recently put more than $1 million into sharp-elbowed anti-Christie attacks in New Hampshire. Rubio has been the target of close to $1 million in negative advertising, mostly in Iowa and mostly by Cruz boosters.

There is unquestioned excitement among the GOP electorate in Iowa for the two front-runners.

On Saturday, Cruz concluded a six-day, 28-stop trek across the state, drawing overflow crowds everywhere — from a pizza restaurant in Pocahontas to a small college in Sioux Center, where hundreds packed the auditorium, spilling into the stairwell and upper level.

“There is no doubt that the Washington cartel is in full panic mode,” said an almost giddy Cruz this past week. “They are in full panic mode because they are seeing on the ground conservatives uniting.”

At other stops, Cruz supporters stood outside in snow and sub-freezing temperatures, unable to get in for a seat, but still trying to listen through open doors. At a Friday morning event in Mason City, 48-year-old Robert Peterson said he was sold on Cruz, even though he said he had never before voted for a Republican presidential candidate.

“It’s time for a change,” Peterson said, standing at the back of the room wearing a red “Cruz 2016” button and holding a red, white and blue Cruz sign. “The status quo has got to go.”

It’s much the same for Trump, who is showing no signs of slowing down after leading most national preference polls since the summer. The brash real-estate billionaire and former reality television star routinely draws thousands of people to his rallies, packing high school auditoriums, arenas, convention centers — even an airplane hangar — across the country.

Supporters began lining up at dawn for a 7 p.m. rally in Burlington, Vermont, this past week, while in Massachusetts and New Hampshire, hundreds stood outside in the bitter cold for hours waiting to get in.

“Folks, we have a revolution going on,” Trump said in Lowell, Massachusetts, marveling at the thousands of people who filled the arena. “People are tired and they’re sick of the stupidity that we’re seeing coming out of Washington.”

In the face of Trump’s prophesied revolution, the GOP establishment is preaching patience.

“I don’t think there’s a sense it’ll be time to panic if Cruz and Trump are on top in Iowa or New Hampshire,” said Katie Packer, who served as deputy campaign manager to Mitt Romney in 2012 and is among Trump’s biggest critics. “We have to let the process play out.”

(AP)