House Speaker Mike Johnson took the stage and immediately addressed the assassination attempt on Trump.

The speaker vowed that the House would thoroughly investigate the incident.

2:05

Mike Johnson pushes for unity, but dismisses 'radical, woke progressive left'

House Speaker Mike Johnson took the stage and immediately addressed last week's assassination attempt on Trump.

"The American people deserve to know the truth. We will ensure accountability, I promise you that," he said.

While he pushed for Americans to unite, he also chastised the "radical, woke progressive left."

Johnson vowed that Republicans would take the House and Senate to support Trump's ideals.

During Louisiana Rep. Steve Scalise's speech, the crowd broke out into a chant of "build that wall" after the House majority leader referenced the border wall.

1:40

'Build that wall' chant breaks out during Scalise's RNC speech

During Louisiana Rep. Steve Scalise's speech, the crowd broke out into a chant of "build that wall" after the House majority leader referenced the border wall.

Scalise said that under Trump, they will "repass H.R. 2" -- the GOP immigration bill that would restart border wall construction and more.

"We will lock down the border and yes, we will finish building the wall," Scalise said.

House Majority Whip Tom Emmer said the GOP has "held the line" against the Biden administration's agenda.

2:22

Fiery Emmer says House GOP is behind Trump

Majority Whip Tom Emmer (R-MN), said the GOP has “held the line” against the Biden administration’s agenda.

"We won't just be holding the line any more" if Trump is elected, he said. "We’ll be moving forward," he added, to loud applause.

"I know firsthand that Minnesotans can't afford four more years of Joe Biden and Kamala Harris," he said, promising that Minnesota would turn red for the first time in 50 years.

Former New Jersey Gov. Chris Christie called on former President Donald Trump to redirect the Republican Party in "a new direction" and to encourage party members to treat others with respect, in the wake of the assassination attempt targeting Trump, in a New York Times op-ed published Tuesday.

"Mr. Trump has the opportunity to rein in some of the worst rhetorical impulses of the Republican Party at its convention this week," Christie wrote.

Christie wrote that Trump's selection of Sen. J.D. Vance as a running mate was not in that spirit.

"Mr. Vance's first reaction to the assassination attempt against Mr. Trump was to turn directly to the current, flawed playbook: demonize the other side and lay the blame at the feet of the Democrats, as if they had pulled the trigger themselves. Clearly, this is not a message of unity in the face of what could have been a national tragedy," he wrote.

Christie, who in January suspended his campaign for president, has not endorsed Trump.

He praised Trump's remarks to the New York Post about changing his own speech and looking to foster unity.

-ABC News' Oren Oppenheim