DES MOINES, Iowa (AP) — Joni Ernst burst onto national politics in 2014 as a gun-toting, hog-castrating, motorcycle-riding candidate who was going to shake up Washington.

One ad featured her at a shooting range firing a handgun as the gravelly-voiced narrator stated, “And when she sets her sights on Obamacare, Joni’s going to unload.”

She won, defeating an establishment Democrat, in some some ways presaging Donald Trump’s defiant candidacy, one that she has enthusiastically supported throughout his presidency.

Now, as the first-term Republican senator seeks reelection, she finds her fate tied to Trump's in a state where the president's support has eroded significantly as voters have harshly assessed his handling of the pandemic, and hers.

Ernst's ads this time advocate not the reversal of the Affordable Care Act, but upholding its most popular provision: somehow guaranteeing health coverage for people with preexisting medical conditions while gutting other provisions in the law.

Trump finds himself locked in a close race in Iowa with Democrat Joe Biden, and Ernst is as well against Democratic challenger Theresa Greenfield.

When the campaign year began, strategists in both parties forecast that Republicans were likely to carry the state easily. But Trump is visiting Iowa on Wednesday, a measure of his difficulty in that he his taking precious campaign time for a trip to a state he won by more than 9 percentage points four years ago.

“I think it’s definitely tough. Walking the tightrope between pleasing the Trump base versus attracting other voters is challenging," said John Stineman, a Iowa Republican strategist unaffiliated with the Ernst or Trump campaigns. “I think if he performs poorly, that makes it hard for her."

Greenfield, a political newcomer and Des Moines businesswoman, is emphasizing health care and a far more robust response to the pandemic, along with emphasizing Social Security and union benefits she received as a young widow.

Unlike in 2014, when the little-known state senator introduced herself as an Iraq War veteran, Ernst, 50, is now balancing her support for Trump with a more moderate tone as Iowa voters show strong signs of returning to their decades-long swing-state form.

“You have the road of the radical left,” she said while introducing Vice President Mike Pence at the Iowa State Fairgrounds in August. “They are paved with abortion on demand. They are paved with the 2nd Amendment rollback.”

Ernst has sounded less partisan notes during recent debates with Greenfield, notably discussing her advocacy on behalf of sexual assault victims. Ernst revealed last year that she had been a victim of assault herself.

She has also highlighted her work with the Senate's premier moderate Republican, Sen. Susan Collins of Maine, supporting a Democratic bill to block the Justice Department from moving forward in court to invalidate the Affordable Care Act.

It's an effort to carve out individuality in an environment so dominated by Trump, and one similar to that faced by GOP Sens. Martha McSally of Arizona and Thom Tillis in North Carolina.

Democrats need to pick up four Republican seats to gain a Senate majority, or three seats and the presidency, considering a Democratic vice president would cast a tiebreaking vote if the party claims the White House.

Early this year, Ernst and Trump were favorites in Iowa. Trump carried Iowa by 9.4 percentage points in 2016 and Ernst surprised four-term Democratic Rep. Bruce Braley by nearly as much in 2014.

But a majority in Iowa disapprove of Trump's handling of the COVID-19 pandemic, while Ernst's favorability sits at just 44%, the Des Moines Register's September poll showed.

Ernst was criticized this fall after saying she was skeptical about government statistics on coronavirus infections and deaths, prompted by a constituent during a campaign stop who suggested hospitals inflated the numbers for financial reasons. Ernst later apologized for her comment during a televised debate.

Greenfield has argued that Ernst has hewed too closely to Trump. In voting to confirm Trump's Environmental Protection Agency head, Ernst is complicit, Greenfield says, in the agency's renewable fuel waivers to oil companies, which forced the closures, some temporary, of at least a dozen-plus ethanol plants in Iowa.

“I just stay focused on holding her feet to the fire for votes,” Greenfield said at a campaign stop in Hiawatha last week.

Ernst has labeled Greenfield a pawn of East Coast power brokers. Advertising dollars have poured into Iowa, with $172 million in total reserved media as of Monday, according to a review of Kantar/CMAG data by The Associated Press.

More of the outside spending is aimed at supporting Greenfield, especially by national Democratic-aligned groups. The National Republican Senatorial Campaign Committee has spent $11.3 million supporting Ernst, according to Kantar.

Greenfield has proven to be a dogged fundraiser herself. The 56-year-old real estate executive raised $28.7 million in the quarter ending Oct. 1. Ernst had outraised Greenfield overall, having begun fundraising early in her term. However, Ernst's campaign has not yet reported a third-quarter total.

Recently, Ernst's tone has swung from her debate's quiet, reflective patriotism to an unmistakable echo of the Trump campaign's more aggressive style. Speaking during a recorded message during the Republican National Committee, she called the Democratic ticket's path one "paved by liberal coastal elites and radical environmentalists."

The RNC appearance underscores how Ernst, who has broken at moments with Trump and chided him publicly for insensitive language, has not tried to distance herself from the candidate who could also help lift her in an 11th-hour surge.

Though Ernst has been campaigning through the state, she declined a request for an interview.

Breaking with longstanding tradition, Ernst will not be alongside Trump at his Des Moines rally Wednesday evening. Ernst, a member of the Senate Judiciary Committee participating in the confirmation hearings of Supreme Court nominee Amy Coney Barrett, will remain in Washington, aides said.

However, the hearings offered Ernst a moment Tuesday to address some of the criticisms against her. Chiding the EPA for interpreting the ethanol waiver laws “for the benefit of oil producers” and in a way “that harmed our Iowa farmers,” Ernst asked Barrett, “How should agencies interpret the laws passed by Congress?”

Greenfield seems content to let Trump, for better or worse, shadow her opponent.

Talking to cafe owner Diane Peterson in Hiawatha last week, Greenfield simply said, “Iowans just want the divisiveness to end.”