Sen. Joni Ernst (R-Iowa) delivered a prominent speech at Wednesday’s Republican National Convention, a prime speaking role to try to appeal to President Trump’s most ardent supporters ahead of her November reelection effort.

During Thursday’s closing night, Rep. Jeff Van Drew (R-N.J.) will also get a speaking slot, a Democrat-turned-Republican in a tough race who wants to fully align himself with Trump.

A few hours later, as Trump formally accepts the nomination at the White House, Sen. Thom Tillis (R-N.C.) plans to be on hand cheering loudly for the president’s pursuit of a second term.

As Republicans head into the home stretch of their reelection bids, they are finding themselves in an increasingly difficult dance about how to handle their political relationship with the man at the top of the ticket.

For nearly four years, these Republicans have been obsequious toward Trump, almost never criticizing him publicly and professing ignorance when questioned about an incendiary remark or tweet by the president. They operated in fear that any tough words would immediately draw the president’s wrath — and anger his MAGA followers.

And in recent months, GOP senators who first won in 2014 and now face their first reelection have rhetorically remained supportive of Trump as he fell behind Democratic nominee Joe Biden. But slowly but surely, the president vanished from their campaign advertising and most communication with voters as they stressed their work in delivering results during the coronavirus pandemic for their states.

For several Republicans in key races, that strategy has left the incumbent in a curious position where they have yet to win over enough of Trump’s supporters in their races and are lagging behind the president, even in states where he is also struggling.

In Arizona last week, the Associated Press published audio of Sen. Martha McSally (R) discussing her similar problems, in which she keeps losing a chunk of Trump voters to former astronaut Mark Kelly, the Democratic nominee whose fundraising haul has allowed him to pepper the airwaves.

“They keep hammering me,” McSally said. “Then somebody actually could vote Trump-Kelly.”

Broadly speaking, Trump has proved to have a significant hold on a certain segment of voters, particularly in more rural regions, that other Republicans struggle to match. But in the suburbs, some Republicans are being punished just as much as Trump by voters who recoiled from the president and his “America First” agenda, no benefit of the doubt given.

Tillis and McSally are the most obvious examples of this struggle for Republicans.

In an NBC News/Marist poll in late July, Biden led Trump, 51 percent to 44 percent in North Carolina, while Tillis trailed Democrat Cal Cunningham, 5o percent to 41 percent.

In Arizona, a CNBC poll in early August found Biden leading Trump, 48 percent to 44 percent, while McSally trailed Kelly, 49 percent to 43 percent.

According to a RealClearPolitics average of recent polls, Trump is receiving 47 percent of the vote in North Carolina, while Tillis is stuck at 40 percent, and in Arizona the president is averaging 45 percent to McSally’s 42.3 percent.

These Republicans are stuck between “the rock and a hard place,” according to J.B. Poersch, the president of Senate Majority PAC, which is closely aligned with Senate Minority Leader Charles E. Schumer (D-N.Y.).

Tillis, McSally and some others need to tack to the right to collect that group of Trump voters who question whether they are true presidential backers, without eroding more support among suburban voters.

This week illustrates how Republicans are handling things differently.

On Monday, as Trump made stops in Charlotte, including at the official gathering of a few hundred RNC delegates, Tillis instead went to a nearby plant that had benefited from the Paycheck Protection Program.

“I’ll guarantee you the president would want me here talking with these businesses,” he told an interviewer on Fox Business Network.

Tillis then declared that he would be at Trump’s speech Thursday on the South Lawn, and he dismissed questions about his lagging support with the president’s backers.

“We’ve got strong support. I was just on a phone call with a number of grass-roots organizations this morning,” Tillis responded.

Ernst, running in a state Trump won by more than nine percentage points, has placed a bet more squarely on the idea that the president will win the Hawkeye State again this year. Asked to speak at the RNC, Ernst did not hesitate.

She is expected to use her speech, which was prerecorded in Iowa, to talk about farm issues and the state’s recovery effort from a derecho storm that ravaged crops and buildings.

Ernst has lagged Trump by about two percentage points in most polls, but her opponent, Theresa Greenfield, is less well-known than Biden, so GOP strategists do not have the same level of concern as they do with McSally and Tillis.

Van Drew is a unique case but has to worry about the same issues.

After spending decades as a moderate Democrat, flipping a longtime GOP seat in the 2018 midterms, Van Drew switched parties during House impeachment proceedings and pledged his loyalty to Trump.

Still, Democrats believe their candidate, Amy Kennedy, has pulled ahead, at least in part because Trump supporters in the rural swath of South Jersey do not trust Van Drew — and his speech Thursday might help shore up what is his new base.

Some Republicans are trying to coach their colleagues into threading this narrow path to victory. “I think you can be part of a greater Republican movement and still be part of identifying as an individual who understands your state and wants to represent that state,” said Sen. Roy Blunt (R-Mo.), who stuck with Trump in 2016 and narrowly eked out a win despite his heavily establishment credentials.

Poersch said he suspects Republicans suffer from three “folk tales” in recent Senate races, the losses of Kelly Ayotte (R-N.H.) and Joseph J. Heck (R-Nev.) in 2016 and Tillis’s own standing this year.

Ayotte and Heck pulled their support for Trump after The Washington Post’s October 2016 report about him bragging of assaulting women, then narrowly lost Senate races. And Tillis tried to create an independent brand in recent years first by sponsoring legislation to protect the special counsel investigation of Trump’s 2016 campaign and then opposing the president’s national emergency declaration to take military money and spend it on a border wall with Mexico.

Within days, Tillis reversed course as he faced Trump’s wrath and a potential primary challenger.

Now, after navigating the primary, Tillis is stuck in another political vise grip.

Poersch chuckled at Tillis, Ernst and others from the GOP class of 2014 now struggling with an unpopular president, after they were swept into office six years ago, accusing their Democratic opponents of not doing enough to stand up to the Obama administration.

“They don’t appreciate how they got elected in the first place,” he said.