This is amazing...
"Nassau is the place to go, ain't no other place I'd rather be. Westchester's for pussies, nothin' stinks like Jersey."
But seriously, I think some of the difference in voting patterns might be due to the housing market. NYC cops living and retiring in Nassau (or Suffolk) is a stereotype for a reason. You don't seem many cops retiring to Westchester because they simply can't afford homes there.
Residential median sale price
County: 2019: 2020: 2021:
Nassau $541,000. $585,000 $620,000
Suffolk $420,000. $470,000 $510,000
Westchester $629,020 $707,500 $750,000
Some Italian cops with mob ties could live in W'chester, that's where Judge Jeanine Pirro lives.
But seriously, NYPD and FDNY should be required to live in the city, and yes outside of Staten Island. Make pay affordable and a good salary.