2016 Presidential Candidates Tweak Messages, Schedules After Orlando Shooting

There are already signs the tone of the race will change this week.

But after the mass shooting in Florida this weekend, which claimed the lives of at least 50 people and injured more than 50 others, there are already signs that the tone and tenor of the campaign this week will be far different than expected.

Trump said last week the address would cover “all of the things that have taken place with the Clintons. I think you're going to find it very informative and very, very interesting.”

In his statement today, Trump excoriated both Clinton and President Obama, who he said “disgracefully refused to even say the words ‘Radical Islam’” in his remarks at the White House Sunday afternoon.

“For that reason alone,” Trump asserted, “he should step down.”

Trump added that Clinton “wants to dramatically increase admissions from the Middle East, bringing in many hundreds of thousands during a first term -- and we will have no way to screen them, pay for them, or prevent the second generation from radicalizing.”

Meanwhile, the GOP candidate caught blowback for a series of tweets he sent over the course of the day, some of which appeared self-congratulatory.

As for Clinton, who was scheduled to hold her first joint campaign event with Obama in Wisconsin this Wednesday after the president’s endorsement last week, she announced Sunday the appearance would be postponed “because of the tragic attack in Orlando."

Her campaign has not announced further changes to her campaign schedule, and she is set to hold an event in Cleveland Monday.

In her own written statement, the Democratic candidate made no mention of Trump. Instead, she called the slaughter at the gay nightclub in Orlando "an act of terror” and “an act of hate."

"We can say for certain that we need to redouble our efforts to defend our country from threats at home and abroad," Clinton said.

“ISIS must be destroyed,” he told reporters Sunday evening. “We have got to everything humanly possible to prevent these types of tragedies from occurring again.”

The shooter, identified by officials as Omar Mateen, called 911 to pledge his allegiance to ISIS after the shooting began, according to law enforcement officials.

ABC’s Meghan Keneally, Corinne Cathcart, David Caplan and Michael Edison Hayden contributed reporting.