Joni Ernst's big RNC moment likely won't be as VP

(CNN)Iowa Sen. Joni Ernst may just be the belle of the Republican National Convention ball, but it's not likely to be as Donald Trump's running mate.

Ernst, who in 2014 wrote her ticket to Washington in part with an ad referencing pig castration, recently told the presumptive Republican candidate she's very focused on Iowa and its role in the upcoming election as a potential swing state.
Shorter Ernst: Thanks for the interest, bless your heart, but I'll pass. (An aide told CNN the senator's focus remained on Iowa.) Fellow Sen. Bob Corker of Tennessee also let Trump know this week he would decline the offer as well.
    But that doesn't mean Ernst won't have a big spotlight on her when the Republicans convene in Cleveland on July 18.
    Trump has chosen Ernst for one of the top speaking slots where she will make national security-focused remarks, a Republican adviser told CNN. She will speak on Monday during prime-time, according to a source familiar with the matter and a Republican adviser.
    Ernst, who serves on the Armed Services and Homeland Security committees, is the first female combat veteran to serve in the Senate. She served as a company commander in Kuwait and Iraq, and retired as a Lieutenant Colonel in the Iowa Army National Guard last year after 23 years of service.
    Ernst met with Trump, alongside his campaign manager Paul Manafort and RNC Chairman Reince Priebus, on July 4 in New Jersey. The support of the highly touted rising star signals a new phase in unity as the GOP seeks to coalesce.
    "I have offered my services and I think it would be a nice opportunity," Ernst told CNN when asked about a potential speaking slot on Wednesday.
    Despite speculation that Ernst is on Trump's vice presidential shortlist, Ernst did not directly tell the presumptive GOP nominee she is not interested in being his running mate, but did convey to him that she wants to focus now on Iowa.
    "We talked a lot about Iowa. Iowa is going to be really important in the upcoming election. So what I visited with him about is just how great it is to get out and met with people, I do a 99-county tour so I encouraged him to get out and meet as many people as possible," Ernst said.
    Ernst, 46, first propelled to the national spotlight during her 2014 campaign with her "Make 'Em Squeal" ad, demonstrating her no-nonsense toughness, despite her "Iowa nice" demeanor.
    "I grew up castrating hogs on an Iowa farm. So when I get to Washington, I'll know how to cut pork," she said with a smile, alongside a squealing pig.
    Ernst grew up in Montgomery County, Iowa, where she still lives with her husband, Gail, and teenage daughter, Libby. Her Midwest farm upbringing provides a contrast to Trump's, an everyday appeal that will help the businessman with suburban voters.
    Iowa is expected to be a swing state in November, and Ernst's high profile at the convention could be key to solidifying support for Trump in the Hawkeye State and throughout the Midwest.
    She was chosen to deliver the Republican response to the 2015 State of the Union, in which she memorably talked about walking to school with bread bags covering her shoes.
    "As a young girl, I plowed the fields of our family farm. I worked construction with my dad. To save for college, I worked the morning biscuit line at Hardee's. We were raised to live simply, not to waste. It was a lesson my mother taught me every rainy morning. You see, growing up, I had only one good pair of shoes, so on rainy school days, my mom would slip plastic bread bags over them to keep them dry. But I was never embarrassed," Ernst said, drawing widespread praise.
    Ernst was careful to stay above the 2016 fray even as 17 Republican candidates crisscrossed her home state. While she did not endorse a candidate ahead of the caucuses, she hosted a handful of presidential candidates at her inaugural "Roast 'n Ride" event in June 2015, rolling in on her Harley-Davidson motorcycle alongside Wisconsin Gov. Scott Walker.
    And she appeared on the campaign trail alongside Marco Rubio days before the caucuses, introducing, but not endorsing, her friend and Senate colleague.
    Ernst could help bolster Trump's credibility with female voters, although she has been subtly critical of Trump's comments on women, expressing concern to reporters in a September 2015 conference call. Without singling out Trump, she said, "I would like to think our presidential candidates would at least respect other people, whether male or female."
    And in April, she told Des Moines affiliate WHO that she was "disappointed" with the name calling and finger pointing in the race.
    "I would encourage women to stand up and say, 'You know what, I'm not going to put up with his nonsense, but I do agree with him on this policy,'" Ernst said. "Sometimes we have to look beyond certain aspects of a person and figure out do we agree. And he may not be able to overcome some of those aspects."