DES MOINES Ted Cruz and Marco Rubio are poised to intensify their rivalry as the first and third place finishers head to New Hampshire with clear momentum following a race that saw them battle in the trenches for conservative voters.

Assumptions about where Cruz and Rubio fit into what has been a jumbled GOP primary have long held that the Texas senator owned the conservative vote, with his Senate colleague from Florida a better fit for mainstream Republicans. In terms of their sources of fundraising, it's true that Cruz has energized grassroots contributors, and that Rubio is more attractive to the wealthy donors who hail from the party's so-called establishment.

But among actual voters, there is an incredible amount of crossover. Cruz appeals to the conservative voter's id, offering a vision of principled, uncompromising governance. Rubio plays on their heartstrings, with promises to win the presidency by winning converts to the conservative cause. As revealed in interviews over several weeks and multiple early primary states, Rubio voters' second choice is Cruz, and visa-versa.

A few days before the Iowa caucuses, then-undecided likely caucus goer Loren Looft told the Washington Examiner during a Cruz campaign rally in conservative northwest Iowa that he had pared his choices to the Texan and Rubio. "Sen. Cruz, he shares a lot of the same values that I share, so that's very appealing to me," Looft, 54, said. "The thing about Sen. Rubio, I think he's the most electable of the two candidates."

Cruz won the Iowa caucuses Monday with 28 percent of the vote, followed by New York celebrity businessman Donald Trump, at 24 percent, and Rubio, who finished a surprisingly strong third at 23 percent. Cruz's superior get-out-the-vote operation allowed him to weather a record 170,000 voter turnout that was supposed to ensure a Trump victory. Rubio absorbed more than $25 million in attack ads over the past eight weeks, more than any other candidate.

As Rubio fended off attacks from former Florida Gov. Jeb Bush and New Jersey Gov. Chris Christie; and Cruz defended himself against a withering assault from Trump, the two friends and senators slowly but steadily escalated their competition for the 2016 nomination.

Cruz hit Rubio for his past support of comprehensive immigration reform that included a path to citizenship for illegal immigrants; Rubio slapped Cruz for running as a "consistent" conservative despite a history of changing positions — on trade, immigration and defense issues. With the New Hampshire primary one week away, and the next presidential debate scheduled for Saturday, tensions are sure to rise further.

The Cruz campaign in the final days before Monday's caucuses was running a television spot that accused Rubio of being untrustworthy and lying about his positions on immigration and other issues. Rubio responded by calling the ad deceitful and, and hasn't hesitated to call Cruz a liar. Rubio's supportive super PAC, Conservative Solutions PAC, has been running ads targeted Cruz that accuse him of being politically "calculated."

Last fall, as Cruz sprinted out to a lead in Iowa and second place in most national polls behind Trump, Rubio's path to the nomination appeared obstructed by the collection of so-called GOP establishment governors and former governors in the race: Jeb Bush of Florida, Chris Christie of New Jersey and John Kasich of Ohio. In New Hampshire, which allows independents to vote in primaries, this is a dynamic that could theoretically play out.

But as it turns out, Rubio tends to appeal to voters who want a conservative change-maker in Washington. They tend to look approvingly on Cruz, viewing him as principled and willing to fight D.C.'s entrenched power structure. They also want to win the general election in November and believe Rubio might be more equipped to work with Congress to advance conservative policies. But either way, they're unlikely to gravitate toward "establishment" candidates.

Back in December, Rubio supporter James Frantel, 47, said while attending a campaign rally for the Floridian in Las Vegas that he likes Cruz because the senator "isn't afraid to speak his mind" and he's a "firebrand." But Rubio was his first choice "he's youthful, he's energetic, very articulate, strong on foreign policy — and he's someone who could actually beat Hillary Clinton."

In the closing days of the Iowa campaign, voters here tended to like Cruz because of his conservative values and image as an unwavering fighter. As Rubio supporter Rob McGee, 47, of Cedar Rapids, said: "He upsets the establishment a little bit more." And they tended to prize Rubio's electability and the prospect that he could grow the Republican Party and convince new voters to embrace conservatism in November.

The higher turnout and more ethnically diverse makeup of the presidential electorate has increasingly favored the Democrats.

But electability alone doesn't explain Rubio's better-than-expected finish or whom he appeals to. Outside of his flirtation with immigration reform, Rubio is conservative at heart, and voters pick up on that. The senator only ended up in the Senate because he defeated a sitting Republican governor in his 2010 Senate primary, running for the office against the wishes of the GOP establishment on Capitol Hill.

Lauren Hammerberg, 51, who said on her way out of a Rubio campaign rally on Sunday in Cedar Rapids that she expected to caucus for the senator, said she liked "everything" about him. "He's super conservative; he's Catholic. He said everything I wanted to hear."