Presidential candidates are in an all-out sprint in Iowa with the caucuses only 30 days away.

Campaigns are sharpening their attacks, doubling down on time and resources spent in the state, and placing their final bets on the ad buys and infrastructure they hope will bolster their get-out-the-vote efforts.

On the Democratic side, Hillary Clinton Hillary Diane Rodham ClintonBarr criticizes DOJ in speech declaring all agency power 'is invested in the attorney general' Virginia Democrat blasts Trump's 'appalling' remark about COVID-19 deaths in 'blue states' The Hill's Campaign Report: Biden asks if public can trust vaccine from Trump ahead of Election Day | Oklahoma health officials raised red flags before Trump rally MORE holds a substantial lead in the polls, though Democrats are warning the front-runner against complacency. They point to the enthusiasm gap she faces against Bernie Sanders Bernie SandersSenate Republicans signal openness to working with Biden Hillicon Valley: DOJ indicts Chinese, Malaysian hackers accused of targeting over 100 organizations | GOP senators raise concerns over Oracle-TikTok deal | QAnon awareness jumps in new poll Schumer, Sanders call for Senate panel to address election security MORE, who will be looking to marshal his substantial grassroots support in a state that sent Clinton’s 2008 hopes into a tailspin.

ADVERTISEMENT

But most of the intrigue is on the Republican side, where 11 candidates are still vying for the party’s nomination. Political watchers are expecting a record GOP turnout at the caucuses, as well as a substantial winnowing of the field in the weeks that follow the Feb. 1 vote.

“Iowa doesn’t always define the race, but it can chop the field in half or at least thin the herd,” said Jamie Johnson, a long-time GOP operative in the state. “It will certainly separate the contenders from the pretenders and sling-shot some into New Hampshire while sending the rest home.”

Ted Cruz Rafael (Ted) Edward CruzLoeffler calls for hearing in wake of Netflix's 'Cuties' Health care in the crosshairs with new Trump Supreme Court list 'Parks and Rec' cast members hosting special reunion to raise money for Wisconsin Democrats MORE and Donald Trump Donald John TrumpBarr criticizes DOJ in speech declaring all agency power 'is invested in the attorney general' Military leaders asked about using heat ray on protesters outside White House: report Powell warns failure to reach COVID-19 deal could 'scar and damage' economy MORE are presently jockeying atop the polls and are the consensus favorites among insiders in the state.

Cruz has been on a sharp upward trajectory, catching and in some polls passing Trump.

The Texas Republican senator has won the backing of some of the most influential conservatives in the state, including Rep. Steve King (R-Iowa) and Christian leader Bob Vander Plaats, who has backed the last two caucus winners.

The state’s massive bloc of evangelical voters has been moving steadily into Cruz’s corner. He has raised tens of millions of dollars, impressed with his campaign organization, and will kick-off the new year with a six-day, 36-county “Cruzin’ to Caucus” bus tour across the state.

Still, one month is an eternity to carry a front-runner’s mark.

Marco Rubio Marco Antonio RubioHillicon Valley: DOJ indicts Chinese, Malaysian hackers accused of targeting over 100 organizations | GOP senators raise concerns over Oracle-TikTok deal | QAnon awareness jumps in new poll Intelligence chief says Congress will get some in-person election security briefings Republican Senators raise concerns over Oracle-TikTok deal MORE has had Cruz on the defensive over his immigration record, and outside groups have been spending heavily against him.

“I think he’s built to withstand the scrutiny that comes with being the front-runner,” said Eric Woolson, a veteran of several GOP presidential campaigns in the state. “He’s done too good a job of building a caucus night organization here.”

Trump, meanwhile, has a terrifying message for his rivals.

“I have spent very little (and am in 1st place),” Trump tweeted this week. “Now I will spend big in Iowa/N.H./S.C.”

The long-time front-runner is reportedly preparing an ad blitz that could reach $2 million a week in the state. Paid advertising hasn’t moved the needle much this cycle, but could help put Trump, who has already benefitted greatly from outsized media attention, over the top.

Republicans say that Trump’s ground game, which has been the source of intense speculation, is the real deal. That’s critical, as Trump is banking on turning out a diverse coalition of caucus-goers that haven’t historically participated in the process.

A poor showing in Iowa could doom Trump, as his flashy polling numbers and record of “winning” are central to his pitch.

“He’s definitely for real out here,” said one Iowa Republican official who requested anonymity. “The question is whether the people they’ve identified as supporters will turn out. I’m not convinced they will, but if he can turn out just half of them he could blow the top off this thing.”

The rest of the GOP field are considered long-shots for a top finish, but several candidates could punch their tickets out of the state with strong showings.

Republicans in Iowa are down on Ben Carson Benjamin (Ben) Solomon CarsonBiden cannot keep letting Trump set the agenda The Hill's 12:30 Report: Trump heads to New Hampshire after renomination speech Five takeaways on GOP's norm-breaking convention MORE, who spent about a month challenging Trump atop the polls, but has fallen sharply since the focus of the race turned to national security after several high-profile terror attacks. Carson’s campaign is in chaos, with his top lieutenants resigning on New Year’s Eve.

Still, Carson is likely to raise more money than any GOP contender this quarter, a sign there’s still strong grassroots support for his candidacy.

Carson will benefit from a plucky super-PAC that has been on the ground in Iowa since before he even announced his bid. Rather than focusing on advertising, the group has been singularly working on get-out-the-vote efforts.

Republicans also say not to sleep on a candidate running in the establishment lane, noting that Mitt Romney nearly won the caucuses in 2012.

That lane is packed, however, with Rubio, Jeb Bush, Chris Christie and John Kasich each holding out hope that they’ll be the candidate the establishment rallies behind. Fierce infighting broke out this week among the group, underscoring the urgency many in the party feel for finding an alternative to Trump or Cruz.

Still, the crowded lane will make it difficult for any of these candidates to break away.

But whoever finishes first among them — even if it’s a distant third place overall — will be in good position heading into the more mainstream waters of New Hampshire.

Of these contenders, Rubio is easily the favorite. Besides Trump and Cruz, he’s the only other candidate polling in the double-digits in Iowa, according to the RealClearPolitics average.

However, Rubio has faced questions about his commitment to the state. He has spent relatively little time in Iowa, preferring instead to run a more nationally focused campaign reliant on strong debate performances and Fox News appearances.

Rubio has spread his bets to each of the carve-out states without committing to any one in particular. He appears to be getting serious about Iowa now, having just completed a three-day bus tour of the state with Rep. Trey Gowdy (R-S.C.).

“They haven’t put in the work here, I’m just not impressed with their effort,” said Woolson. “But he very well could finish third, and we’re going to be talking a lot about whoever finishes third heading into New Hampshire.”

Bush’s strong infrastructure seems to have him set up to outperform his current standing in the polls, but his numbers are so low right now that it might not matter. Christie is also generating buzz – he counts some influential business conservatives in Iowa as allies – but he’s only made a passing nod to the state.

On the Democratic side, Clinton has pulled away from Sanders and now leads by 12.5 points in the RealClearPolitics average of polls.

But Democrats note that Sanders continues to pull huge crowds on the campaign trail and raise boatloads of money from his committed base of grassroots liberals.

“His supporters are engaged and enthusiastic and want nothing more than to take down the front-runner in Iowa,” said Democratic strategist Andrew Feldman.

If Sanders can pull the upset, he’ll head into New Hampshire the favorite, although most believe Clinton will face smooth sailing after the first two states.

Still, the Clinton campaign wants to avoid any suggestion she’s vulnerable.

Many Democrats still believe the Clinton campaign, recognizing the need to avoid a repeat of her disastrous 2008 third-place showing, will turn out in force to deliver a victory.

“She has a great organization in Iowa, knows the caucus system and remains the favorite there,” said Democratic strategist Craig Varoga.