Dallas — President Trump calls this week's Republican National Committee midterm convention a "rally like never before," and an opportunity to celebrate his administration's first two years ahead of the November elections. But the convention is taking place as the GOP faces headwinds over the unpopular war in Iran, and Mr. Trump's approval ratings have continued to slip.While the president may say he's reserving the stage for Republican candidates in competitive races, CBS News has learned dozens in the closest contests nationwide are expected to be no-shows.Republican leaders and Trump allies are gathering for two days at a downtown Dallas arena, and are holding other off-site donor events and discussions centered around topics like domestic energy production. Loyal Trump supporters are coughing up five-digit sums to their respective national fundraising committees for a ticket. But other Republicans running in competitive races are opting to save the money and campaign in their home districts or states. CBS News attempted to contact 60 battleground gubernatorial, Senate and House candidates, and only four confirmed they would attend the convention. Five told CBS News they would not be going to Dallas, while the vast majority, 51 candidates, did not reply to CBS News' queries. Still, more than two dozen are scheduled to speak at the event, according to the RNC. "Our bosses are back home," said Republican Rep. Brian Fitzpatrick, who is running for reelection in a Pennsylvania district Mr. Trump won by fewer than 300 votes in 2024 and is not planning to attend the convention. "Times are tough, and we need to be listening to everything they're saying about the struggles that they're encountering in their budgets and their kitchen table and their businesses, healthcare and act on it. That's the way the system's supposed to work … not going to some convention center holding signs up."National parties historically hold nominating conventions every four years. Not since 1982, when Democrats last held a midterm confab, has either party met this way during the off-year elections. The Dallas event, at the American Airlines Center, is expected to look more like a highly produced, extended political rally headlined by Mr. Trump than a typical convention, where the party would conduct official business such as formally selecting a presidential nominee. But there are thousands of balloons in nets already hoisted into the arena ceiling, a sign they'll likely come tumbling down during Thursday's convention finale.