2024 RNC, recast by Trump assassination attempt, kicks off Monday

The attempted assassination of former President Donald Trump has thoroughly altered the stakes and tone of the Republican National Convention in Milwaukee, which kicks off Monday, just two days after a shooter opened fire at the former president's Pennsylvania rally, grazing Trump's ear and leading to a spectator's death.

Trump arrived in Milwaukee Sunday afternoon, ahead of the RNC's start on Monday. In a social media post Sunday, Trump indicated that he was going to delay his trip, but decided he wouldn't allow a "shooter" to change his scheduled plans to head to the RNC.

U.S. Secret Service and other officials said Sunday there are no plans to expand the security perimeter and that there are no known threats.

Ahead of the shooting at his rally, the GOP convention was gearing up to be an extravagant event centered around symbolic, Trump-era Republican ideas and party unity, sealed on Thursday with the third nomination of the former president.

MORE: Trump shooting live updates: Apparent explosives in suspect's car, sources say

Now, the gathering of more than 50,000 attendees -- including an expected 2,400 Republican delegates -- is slated to maintain its original programming with a high-stakes atmospheric adjustment. The convention will now be seen as a time to reunite the Republican Party as energized delegates, party leaders and rising stars converge on Milwaukee.

"Unite America!" Trump wrote on social media on Sunday afternoon.

On Saturday evening, in the wake of the shooting, the Trump campaign indicated that they'd proceed with the convention as scheduled in attempts to move forward from the tragic event.

"President Trump looks forward to joining you all in Milwaukee as we proceed with our convention to nominate him to serve as the 47th President of the United States. As our party's nominee, President Trump will continue to share his vision to Make America Great Again," the Trump campaign said in a statement.

The RNC comes at a crucial time when stakes are high. Once Trump is nominated on Thursday, locking him in as the Republican candidate, he is set to take on President Joe Biden as the Democratic Party grapples with whether Biden should remain at the top of the ticket following his debate performance.

In another sign of Republican unity, Trump's former competitor Nikki Haley received an 11th hour invitation to speak at the convention. Haley is slated to speak Tuesday night, a source confirmed to ABC News.

The convention will focus on themes regarding national security, immigration and the economy -- three key issues for voters in 2024. Both Trump and Biden will be looking to make their case to Americans on these issues in what's expected to be a close contest in November.

Following the shooting at Trump's rally, Republican National Committee chair Michael Whatley stressed the fortified security perimeter around the Fiserv Forum, the location of RNC events, during a Fox News interview on Sunday.

"The arena's set, the security is here and we feel very comfortable that we're working with the Secret Service," Whatley said. "We're working with 40 different law enforcement agencies in terms of what that security is going to look like, and this is going to be a facility where we're going to be able to have 50,000 delegates and alternates and guests and members of the media who are going to be here and who are going to be safe. That's very critical for us," Whatley said.

And while the political stakes have no doubt been altered, Whatley emphasized that any impact was secondary, and clearly not the priority.

"I think right now, we need to be praying for these families that have been affected. I think we need to be grateful that President Trump is alive and is actually going to be here. And certainly we look forward to him being here in Milwaukee, and I think it's going to be tremendously important for him to be here and to deliver that message to America."

MORE: How to watch, what to know about the 2024 RNC

And underneath the impacts of the consequential event over the weekend, the GOP still has party business to attend to: finalization of platform, rules and committee proposals that were adopted last week by RNC members at their summer meeting in Milwaukee.

With the ousting of former committee chair Ronna McDaniel earlier this year, the RNC underwent a total leadership metamorphosis and the two new incoming co-chairs were handpicked by Trump: staunch ally Whatley and Lara Trump, the former president's daughter in law.

With that new leadership came the ushering in of refreshed priorities, chief of which was the creation of a new party platform and rules, which took firm shape at the group's summer meeting, just a week before the convention, also in Milwaukee.

There, sub-committees crafted proposals rubber stamped by Trump to the chagrin of some RNC members. The overhaul of the party's platform reframed where the party stood to align with many of Trump's current policy positions.

Language changes especially around abortion, notably the lack of backing a ban on the procedure, motivated members to file minority reports to wedge firmer anti-abortion language back into the platform. Even Trump's former vice president, Mike Pence, called the changes "a profound disappointment."

A group of members will likely attempt to challenge the changes at the full committee meeting on Monday afternoon, though Whatley told ABC News earlier in the week that he expects the platform to pass.

MORE: After Trump assassination attempt, Biden campaign pauses ads, events, attacks

Even with the intra-committee dust ups, the unique splitscreen the GOP has inherited -- of their party in lock-step behind one nominee while the Democratic Party continues to grapple with growing dissent at Biden is not going unmentioned.

"The Democratic Party right now is a party in panic. The Democrats are in disarray. We've all seen that play out in the last several weeks and that continues. I will tell you, we know who our nominee is going to be. It's gonna be Donald Trump and you cannot say the same for the Democrats right now," Wisconsin GOP chair Brian Schimming said Thursday.

There is a strategic opportunity in having the RNC in Milwaukee. Wisconsin is a crucial battleground state that both Trump and President Joe Biden are looking to win in November.

"Hosting the 2024 Republican National Convention in Wisconsin is both an honor and a testament to the importance of this state in November. Wisconsin is critical for Republicans to win back control of the White House and United States Senate. I am confident that by the time this convention ends, President Trump and all Republicans will leave energized," Schimming said in a statement to ABC News.

2024 RNC, recast by Trump assassination attempt, kicks off Monday originally appeared on abcnews.go.com