Nearly every candidate that Donald has backed in 2025 and 2026 elections has lost (excluding primaries, which I don't really count), and that's been true in both red and blue states and in many districts he won by double digits in 2024.
This isn't a scenario where we're expecting an outcome simply due to polling. There is plenty of real-life, empirical evidence that Republicans are fucked.
Consider how historically unique it is that Republicans and Democrats have angered people to such an extent that we might get a dozen socialists elected this year.