A total of 18 Republicans and Democrats are running for Missouri’s U.S. Senate seat.

But most of the attention is on two contenders: incumbent Claire McCaskill and Attorney General Josh Hawley.

Those two candidates and their allies have been sparring for months, providing a prelude to what could be one of the most expensive and contentious national elections of the 2018 election cycle.

Before they can move onto the general election, McCaskill and Hawley need to win their primaries on Tuesday. McCaskill, a two-term senator, is expected to win easily against six Democrat opponents — including St. Louis activist Carla Wright and perennial candidate Leonard Steinman. Most of Hawley’s 10 Republican adversaries haven’t raised much money or gathered significant support.

For their part, Hawley and McCaskill are generally ignoring their primary opponents — and placing their focus on each other. McCaskill often refers to Hawley as her “likely” opponent in November. And many of Hawley’s statements about his positions on issues zero in on his differences with McCaskill, as opposed to his GOP opponents.

Third-party groups aligned with McCaskill and Hawley have already dumped millions of dollars into television ads. And Hawley received help from national Republican Party organizations before the primary, which has upset GOP candidates Austin Petersen and Tony Monetti.

Back in the fray

Credit Carolina Hidalgo | St. Louis Public Radio GOP U.S. Senate hopeful Josh Hawley greets President Donald Trump at St. Louis Lambert International Airport in April.

The fact that Hawley jumped into the U.S. Senate fray is not lost on people who have closely watched his rapid political rise.

Back in 2016 when he was running for attorney general, Hawley used his lack of elected experience as an asset — and blasted his Republican and Democratic opponents for trying to climb the “political ladder.” During an October 2016 appearance on Politically Speaking, Hawley stated: “I am running to be attorney general of Missouri — and that’s the job that I want to do.”

Why the change of heart? Hawley explains it like this:

“I think our way of life is at stake,” Hawley said late last month. “The middle-class way of life that I grew up with in Lexington, Missouri, that has sustained our state and our families and our communities and our churches all over our state — it’s at risk.”

Hawley blames “uncontrolled immigration, jobs going overseas and liberal judges.”

“And right now what happens in the United States Senate is as critical as anywhere else in the country,” he added.

The former Lafayette County resident is a graduate of Stanford University and Yale Law School. A former University of Missouri-Columbia professor, Hawley’s claim to fame on the 2016 campaign trail was his involvement in the Hobby Lobby case, in which he argued paying for contraception under the Affordable Care Act violated his client’s rights.

Hawley has received most of the institutional and financial support of the GOP primary field. That includes endorsements from President Donald Trump and Vice President Mike Pence, who have both held fundraisers for Hawley. Hawley is emphasizing his support of Trump’s judicial nominees and tax cuts.

“Missourians voted for this president by almost 20 points — a huge and significant portion of that was his commitment to putting constitutionalist judges on the bench,” Hawley said. “It was a big, big deal. And you can see that in the outcome of the vote.”

Unlike McCaskill, Hawley has said he supports the goal of Trump’s tariffs — which he says is trying to get other countries to agree to better trade deals. He also stresses his opposition to abortion rights and his desire to allow fewer undocumented immigrants into the country.

“We’ve got to get an immigration system that actually works for our people,” Hawley said. “And I’m thinking in particular our workers in the state. You know, one of the things that mass illegal immigration does is it drives down wages — in addition to the drugs that we see come into this state as well as crime. But also, huge amounts of immigration — even legal immigration from low and unskilled workers — those folks compete with American workers who need good paying jobs.”

Petersen and Monetti loom

Credit Jason Rosenbaum I St. Louis Public Radio Tony Monetti and Austin Petersen

Of Hawley’s 10 Republican opponents, only two have raised at least $200,000 — Petersen and Monetti. Both have been trying to showcase their conservative credentials, contending they are the best candidate to appeal to Missouri’s Republican electorate.

Petersen, of Peculiar, Missouri, first ran for office in 2016 as a Libertarian presidential candidate. He lost the nomination to former New Mexico Gov. Gary Johnson. Petersen decided to run for the U.S. Senate as a Republican after recommendations from his supporters.

Since entering the race, Petersen has gained some attention for giving away firearms, getting suspended from social-media platforms and accepting Bitcoin as campaign contributions. He’s emphasized some differences from Trump — such as his opposition to steel and aluminum tariffs. And he’s expressed an aversion to authorizing military force in foreign countries and sustaining the war on drugs.

“I do believe that we will be getting a certain percentage-point bump based on the fact that people who have not historically voted in Republican primaries will cross over to do so,” Petersen said. “Libertarians have told me they will do so. Independents have told me they will do so. And Democrats who don’t like Claire McCaskill have told me they will be voting in the Republican primary.”

Monetti is a Warrensburg resident who has never run for public office before. The longtime restaurateur has stressed his military background, which included flying the B-2 stealth bomber.

Since jumping in to the race, Monetti has held a rally that featured former Alaska Gov. and vice presidential candidate Sarah Palin. He brushes aside the idea that he can’t match up to Hawley in the primary.

“Let’s be real: Everybody tells me, ‘You can’t win. You don’t have the name I.D. You don’t have the money.’ Well, can’t never did anything, that’s the way I look at it,” Monetti said. “And that just fires me up and excites me even more. When I was at the Air Force Academy, both my roommates quit. And the upperclassmen told me, ‘You need to quit, you don’t have what it takes.’

“But I looked them in the eyes and laughed and said, ‘No, sir, I’m going to make it,’” he added.

Both Monetti and Petersen were critical that the Republican Party national committee decided to help Hawley before the Aug. 7 primary. That will likely allow Hawley to conserve campaign money if he were to win the primary, since most third-party groups can take donations of unlimited size.

Petersen in particular has questioned the wisdom of Trump getting involved in Missouri’s GOP primary — pointing to how his involvement in Alabama’s Senate primary ultimately backfired. “The last time the president interfered in an election, we got a Democrat in Alabama,” he said.

With Trump’s approval ratings in Missouri higher than the national average, Hawley believes the president will be an asset in November.

“I hope he’ll be in Missouri often,” Hawley said. “You know, President Trump won Missouri by 19 points for a reason. It’s that he understands that our way of life here is under threat.”

Follow Jason on Twitter: @jrosenbaum