DOVER — Republican presidential candidate Donald Trump is coming to Delaware this week, his campaign announced.

In advance of Delaware’s primary on Tuesday, Mr. Trump will speak at the Delaware State Fairgrounds in Harrington on Friday afternoon.

The event will take place in the fairgrounds’ Quillen Arena, located near the main gate, at 3 p.m., with doors opening at noon.

The news has created excitement among Delaware Republicans who are eager to take advantage of a rare visit from the party’s presidential front-runner.

Mike Harrington Sr., the Kent County honorary chairman for the Trump campaign, said Monday at the ribbon cutting for the campaign’s Dover office that Mr. Trump would visit the state.

The date and location were finalized Tuesday, he said Wednesday.

Mr. Harrington is excited not just that Mr. Trump will be speaking in Delaware but that he will be in Kent County.

Trish Rodriguez, president of the Kent County Republican Women, said Mr. Trump “has excited an energy in the Republican Party that I haven’t seen in years.”

Donald Trump

Mr. Harrington said at least half of the phone calls the campaign volunteers have been making have been received positively.

He believes Mr. Trump’s popularity stems from his outsider status and business experience.

“He’s saying what everybody else is thinking and afraid to say,” Mr. Harrington said.

As a small state with few delegates in play, Delaware often is ignored by presidential candidates. Eventual Republican nominee Mitt Romney made a brief stop here in 2012, the same year fellow GOP candidate Newt Gingrich spent substantial time downstate. The then-Sen. Barack Obama gave a speech in the Democratic stronghold of Wilmington when he was campaigning in 2008, and Republican candidates George W. Bush and Steve Forbes visited in 2000.

While the visit could sway some voters, Mr. Trump already is expected to win Delaware, according to political operatives and the few polls that forecast the state race.

The Quillen Arena, site of Friday’s rally, can accomodate anywhere from 2,700 to 10,000 people depending on the layout. There is room for about 2,700 to 3,100 in the bleachers around the arena, with space for another 5,000 to 7,000 people sitting in chairs or standing, Danny Aguilar said.

Mr. Aguilar, the assistant general manager for the Delaware State Fair, said Mr. Trump’s campaign reached out about a week ago. The two sides then worked out payment and the timing.

While the event will brings thousands of people to the area, Mr. Aguilar is not worried about the crowd. The annual fair draws thousands per day and last year’s Delaware Junction Country Music Festival had a crowd of about 35,000.

Security will be handled by Delaware State Police and by Mr. Trump’s campaign — including Secret Service agents.

Harrington Raceway and Casino, as well as other fairgrounds events happening at or near the same time, will not be disrupted, Mr. Aguilar said.

Some elected officials could be among those present for the rally Friday. Sen. Colin Bonini, R-Dover, for one, is planning to attend.

“I think Donald Trump’s message is our government is broken in many ways and that we need strong leadership to fix it and I agree with that,” said the senator, who has announced his intentions to run for the Republican nomination for governor.

Meanwhile, the Maryland State Education Association — the teachers’ union — called on the Worcester County school system to keep Trump from using a school for a rally Wednesday.

Union president Betty Weller said in a statement Tuesday that “Trump and his divisive, fear-mongering rhetoric have no place in the halls of Maryland’s public schools.”

She also said Trump’s “eagerness to bully minorities” would be unacceptable behavior from students.

A school system spokeswoman said Trump is paying almost $5,000 to use the gym.

Clinton campaign

The campaign for the Democratic front-runner will have an event in Kent County at the same time Mr. Trump speaks.

Mothers of the Movement, four women whose children were killed by gun violence or alleged police brutality, will campaign for Hillary Clinton at Delaware State University.

Maria Hamilton, mother of Dontre Hamilton; Gwen Carr, mother of Eric Garner; Nardyne Jefferies, mother of Brishell Jones; and Cleo Pendelton, mother of Hadiya Pendelton, will speak at Longwood Auditorium at Delaware State University at 3 p.m.

The Associated Press also contributed to this article.