Ted Cruz took a break from the campaign trail on Tuesday to dive headlong into an aggressive Capitol Hill attack on mainstream climate science — the kind his fellow Republican presidential contenders have mainly sought to avoid.

Less than eight weeks before the crucial Iowa caucuses in which he’s leading the latest polls, Cruz convened a Senate subcommittee hearing where he criticized environmentalists as “alarmists” and questioned “the objectivity of climate research." Also joining the hearing were a half-dozen Democrats, only too eager to get another chance to lampoon the GOP as a party that opposes science.

"The only thing that requires a serious scientific investigation is why we are holding today’s hearing in the first place,” Sen. Ed Markey (D-Mass.) said.

Cruz’s main thrust was an argument that has long been a talking point among right-wing climate skeptics — that some satellite records show that global temperatures have barely budged since 1998. (Both federal and U.N. reports say 2015 is actually on track to surpass last year as the warmest on record, based on a wide swath of ocean and land measurements.) And, he argues, polar ice is not shrinking as fast as climate scientists have predicted. 

“Global warming alarmists don’t like these data," Cruz said during the nearly three-hour hearing, employing a favorite pejorative to describe environmentalists, mainstream climate scientists and Democrats. "They are inconvenient to their narrative. But facts and evidence matters.”

Afterward, Cruz lamented the “suppression of dissent driven politically by Democrats, by those in control of the funding stream,” of scientists who question the idea of man-made climate change. He also pointed to testimony that carbon dioxide, “rather than being a pollutant, is good for plant life.”

Meanwhile, Cruz’s colleagues in the 2016 White House race were keeping their distance — literally.

Sen. Marco Rubio (R-Fla.), who serves on the same Commerce Committee science panel, was thousands of miles away on a campaign swing through California. Rubio's campaign declined to comment before the hearing — as did former Florida Gov. Jeb Bush, who had warned in a speech in 2013 about Republicans being seen as “anti-science.”

Cruz's message does put him in line with other outsider candidates, including national front-runner Donald Trump — as well as claims by some GOP lawmakers, including Oklahoma Sen. Jim Inhofe, that the idea of man-made climate change is a scientific hoax. But it runs afoul of the message that other Republicans have been hoping to carry in 2016 — that they’re not looking to argue about the science, just the economic damage that they maintain President Barack Obama’s aggressive climate regulations would cause.

Other Republican lawmakers had little to say about Cruz’s hearing.

“It’s not the approach I would take. We’ll just leave it at that,” said Sen. Lisa Murkowski (R-Alaska), who chairs the Energy and Natural Resources Committee. “Senator Cruz is one senator out of 100, his view on climate change is his view on climate change. … The fact that he is running for president allows a different, I guess, spotlight to be put on his opinion.” 

But Hillary Clinton was far less reticent — eagerly using the Cruz-chaired hearing as an opportunity to tie the rest of the GOP field to his views on climate science. 

“Ted Cruz may be the latest candidate to use his office to stoke doubts about climate change, but virtually all the Republicans running for president share his commitment to denial and defeatism about America’s capacity to lead the world in confronting this challenge,” the Democratic front-runner's campaign chairman, John Podesta, said before the hearing. 

Meanwhile, Democrats and a minority witness who attended Tuesday’s hearing accused Cruz of taking isolated data points out of context, while ignoring contradictory evidence. 

The subcommittee’s top Democrat, Michigan Sen. Gary Peters, said Cruz was ignoring the underlying fact that burning fossil fuels creates carbon dioxide, a greenhouse gas that prevents heat from radiating into space. And that heat "cannot just magically disappear. Instead it causes our planet to get warmer," Peters said.

Adding to the political potency of the debate is the fact that some Senate Republicans who are up for re-election have seen their opponents use climate change as a wedge issue against them — something that could complicate the GOP’s efforts to hold onto the chamber in 2016. 

Sen. Rob Portman, who faces a tough race in Ohio, declined to comment on Cruz's approach but said he did not question the science. 

“I do think the other side chooses to misinterpret what I’m saying, but it’s pretty simple: I do think the Earth is warming and I do think human activity contributes to it,” Portman said earlier Tuesday. “I can’t really speak to what he’s going to do. I just know what my views are.”

Democrats weren’t letting up the pressure, saying GOP lawmakers need to go beyond just acknowledging the science.

"Remembering that it’s an election year and remembering that public opinion continues to shift in favor of climate action, you ought to measure Republicans’ support for science and for rationality and for doing the responsible thing in terms of their official actions on the Senate floor and in committee," said Sen. Brian Schatz (D-Hawaii). "And not in terms of how they modify their rhetoric coming into 2016.”

Schatz had dismissed Cruz’s hearing beforehand as “a waste of government resources,” adding: “He's on the wrong side of history.” Markey noted that the hearing fell in the middle of a two-week international climate summit in Paris in which the U.S. and roughly 200 other nations are trying to reach a deal for cutting the world’s greenhouse gas output. 

Cruz wasn’t getting much vocal support from fellow Republicans in the hearing room either. Two Republicans on the subcommittee, Cory Gardner of Colorado and Steve Daines of Montana, joined Cruz on the dais ahead of the hearing, although Gardner left before opening statements. (Gardner had been expecting an FBI briefing on the post-Thanksgiving mass shooting in Colorado Springs.)

Gardner had said before the hearing that he would welcome "a focus on the economic impact" of the administration's climate policies. On the other hand, he said, "I just don’t know if that’s the direction the hearing is going to take." 

One audience is likely to cheer Cruz’s approach, however: Conservatives, who according to polls are far more likely than other voters to think that the existence of human-caused climate change is the topic of hot scientific debate. 

In an ABC-Washington Post poll earlier this month, 70 percent of conservatives said they believe that scientists disagreed about the causes of climate change, while moderates were nearly evenly split on the question. Just 41 percent of conservatives view climate change as a serious problem, according to the poll, compared with 67 percent of moderates and 89 percent of liberals.