Why did Lebanon, PA swing so hard to Trump?

[I spent the winter writing songs about getting better]

This is yes the county seat of hard R Lebanon County, but the city itself usually votes D. But it had an immense swing and Trump won it 52%. He also barely lost (Biden 50-Trump 49) a precinct that Hillary won by 20 points. There's no reason I can see for this, the rest of the county swung Biden, and Lebanon proper does have a non-neglible Hispanic population you didn't see something as extreme in Reading or Lancaster.

So what happened here?

[vitoNova]

Greeks bearing false gifts.

[Mexican Wolf]

I figured it was because of a smaller scale version of the Hispanic/Latino swings we saw in Miami-Dade and the RGV. I noticed when looking at the results of the counties bordering Lebanon (like Lancaster and Berks) that the Lancaster and Reading suburbs swung towards Biden, while the city cores themselves swung towards Trump. Since Lebanon City is much smaller than either Lancaster or Reading, I guess that swing was large enough to deliver it to Trump.

[Meatball Ron]

I think you answered your own question - according to the Census website, the city was >40% Hispanic in 2019 (you may have been looking on Wikipedia which shows a lower percentage - not sure if that's just because it's 2010 data or if it has a factual error).

While the RGV and South Florida swings were more noteworthy, you do see this sort of trend throughout urban cores. Look at Ritchie Torres' NY-15 (66% Hispanic); Trump got 5% there in 2016 and 13% in 2020.