Trump has reached a point where he is tying with biden in a national poll, so Biden has clearly been gaining a bit of momentum. Why? I personally think that news about his shady behavior coming out in his trial as well as his unpresidential attitude has started to cost him votes. Now, a national poll can only show a trend as it it isn't definitive. In fact, trump leads in the battleground states. But if this trend continues, he will lose. And if Trump loses, then ukraine will get all the aid it needs as the Republicans won't be deferring to his wishes of letting the Russians win. If Trump loses the trial he will probably lose the presidential election as well.
https://www.usatoday.com/story/news/politics/elections/2024/05/06/biden-trump-tie-hispanic-black-younger-voters/73504174007/