It's unproven, but there are multiple sources claiming that Trump called Netanyahu to not get a ceasefire in place to hurt the Harris campaign. Then once Trump was in office, Netanyahu suddenly cooperated and Trump brokered a ceasefire deal. It's not that crazy to think Netanyahu wanted to punish Biden and Harris and might view Trump as an obvious ally (certainly more likely to enable Israel's genocide than the Democrats would).

Either way, Trump has consistently been pro-Israel, and donors to AIPAC tend to be Republicans and Trump himself is one of those donors. In turn AIPAC funds more GOP candidates in elections than Democrats, even while funding both parties (source).

Trump and the GOP are more enthusiastic supporters of Israel, whether this makes them more beholden I'm not sure, but the idea that Biden is somehow more loyal to Israel seems entirely wrong-headed to me, especially as Biden has been openly critical of Netanyahu and was harsher with Israel than expected, esp. for being a typical pro-Israel conservative Democrat.

Maybe Trump cares less about alienating someone like Netanyahu, but who knows - my impression is that these two are more like natural allies. Maybe that relationship will sour with the influence of Saudi Arabia, but Trump won't be concerned about Palestinian civilians being killed and certainly won't have the same pressure from his base to intercede on behalf of Palestinians. If anything, it's the opposite - Trump has immense pressure from his evangelical base to take pro-Israel positions, and it even extends to his family - his daughter Ivanka and her husband, Jared Kushner, are Orthodox Jews who keep kosher and observe the Shabbat, and guess who Trump put in charge of coming up with a "Middle East peace plan" during his first term? Kushner, who came up with a plan criticized for being lopsided and requiring too few concessions from Israel and too many harsh requirements on the Palestinians. Kushner reportedly has business ties to Israel, and Trump illegally negotiated with foreign officials like the Egyptian president to try to kill a UN resolution demanding an end to Israeli settlements.

Anyway, the examples of Trump's loyalty to Israel are extensive (more so than Biden's), even if you're right that Trump's loyalty could shift due to other influences like Saudi.