Live updates: GOP kicks off its first-ever midterm convention

Trump said he anticipates a "tremendous crowd" at the convention but said some Republicans aren't coming due to a lack of space.

"I think we're going to have a tremendous crowd tonight. Sold out. Looks very big. Looks very exciting, and we're going to explain what we've done," Trump said as he was departing Joint Base Andrews for Dallas.

Asked by ABC's Mary Bruce about Republicans in key races who decided not to attend the convention, Trump said that "everybody is coming."

Trump argued that some people were not coming because there wasn't space, saying "we don't have room for 500 politicians."

"We have room for the ones that have a close race if they're slightly behind or slightly ahead or tied, but we don't have rooms for people that are 35 points up and don't need to be there," Trump said.

American Airlines Center in Dallas, where the convention is being held, can hold up to 20,000 people, according to American Airlines.

-ABC News' Isabella Murray and Nicholas Kerr

On the first day of the Republican's Midterm Convention, billionaire Democratic Illinois Gov. JB Pritzker, who is widely seen as a potential 2028 contender, held a press conference with Texas Democrats, where he argued this week’s events at the convention are serving as a distraction from the kitchen-table problems Americans are enduring.

"Donald Trump is hoping that a flashy primetime event will make you forget that well, his trade war is killing costs for families at the grocery store, his war in Iran is killing ranchers and farmers and their way of life,” Pritzker said.

As Democrats work to build a contrast to the Republican agenda throughout the Trump administration, Pritzker highlighted the unprecedented mid-century redistricting fight Texas Democrats endured last year, when many left the state to prevent a vote on new congressional maps in the state.

"In this moment, when America needs a new generation of leaders, fighters willing to stand up against tyranny, Texas Democrats have stepped into the breach. They alerted the nation to these dangers, and Texas Democrats set an example for the rest of America," he said.

Pritzker, who is running for reelection, punted when asked about his 2028 ambitions, but said, "anybody that is showing up here and bootlicking Donald Trump, and that's what this is all about, is probably going to be disqualified in 2028." Pritzker has not ruled out a presidential bid in 2028.

-ABC News' Juhi Doshi and Lalee Ibssa

The speaker lineup for the Republican's midterm convention has been released -- with speeches on Wednesday coming from President Donald Trump, members of Trump's Cabinet and candidates in key midterm races.

Key congressional Republicans such as House Majority Leader Steve Scalise, House Majority Whip Tom Emmer and Senate Majority Whip John Barrasso are set to speak on Wednesday afternoon.

Several battleground GOP candidates will also speak on Wednesday, including Texas Senate candidate Ken Paxton and Georgia Senate candidate Rep. Mike Collins.

Members of Trump's Cabinet will speak: Treasury Secretary Scott Bessent, Attorney General Todd Blanche and Housing and Urban Development Secretary Scott Turner.

Trump is set to take the stage at 9 p.m. ET Wednesday for his keynote address -- finishing out the day's program.

-ABC News' Sarah Beth Hensley

With just 55 days until the high-stakes midterm elections, President Donald Trump and Republicans from across the country will descend upon Dallas, Texas, for two nights to support the slate of candidates running this year and to tout the administration's agenda going into November in the first-ever GOP midterm convention.

The Republican National Committee said the event will articulate "a clear and bold plan of the work [it] will continue to do on behalf of the hard-working and patriotic Americans after we achieve victory in November."

Several notable battleground GOP candidates, running in races that will decide which party controls the House and the Senate, are not attending this week's convention, which comes as Trump's popularity is at a low.

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