Pro-incumbent trends in the tri-state area?

[Wisconsin SC Race 2019]

It's amazing how NY/CT/NJ specifically have strong pro-incumbent trends dating back to the Eisenhower era (and slightly so in Maryland/Delaware too). Every re-election campaign tends to be more supported by these states than the initial run. What explains this? 

[Hydera]

1972 - Nation wide popularity of Nixon

1984 - Nation wide popularity of Reagan and the economic growth at the time benefiting suburbs really big.

1996 - Popularity of Clinton in Northeast burbs and economy recovering from 1990-1991 recession.

2004 - Bush swinging and turning out lots of suburban italian americans and suburban+wwc+"wwc-ish suburbanites"(especially in Suffolk and Staten island)

2012 - Obama hugging Christie made a few suburbanites in NJ either stay home or vote for Obama. As for NY there was a slight swing to romney.

[Metalhead123]

2012 - Obama hugging Christie made a few suburbanites in NJ either stay home or vote for Obama. As for NY there was a slight swing to romney.

There was a 1.32% swing to Obama in NY in 2012

[libertpaulian]

1972 - Nation wide popularity of Nixon

1984 - Nation wide popularity of Reagan and the economic growth at the time benefiting suburbs really big.

1996 - Popularity of Clinton in Northeast burbs and economy recovering from 1990-1991 recession.

2004 - Bush swinging and turning out lots of suburban italian americans and suburban+wwc+"wwc-ish suburbanites"(especially in Suffolk and Staten island)

2012 - Obama hugging Christie made a few suburbanites in NJ either stay home or vote for Obama. As for NY there was a slight swing to romney.

Regarding 2004, I think 9/11 was a factor, too.

[PragmaticPopulist]

Pro-incumbent (or anti-incumbent trends) tend to be inconsistent, even though I find them interesting. I kind of doubt that there will be a pro-incumbent trend in the tri-state area in 2020.