This fiscal nonsense is sold by local politicians who say they are doing it to "improve" things.
You can bet those politicians are involved with/connected to/supported by/financed by real estate firms.
"We're going to raise your property values. The town is going to become a more attractive place."
Of course the sales job will ignore the fact that the "higher property values" will mean higher taxes on each property that has "higher values"; and that for some the higher taxes will be budget busters; and that for some the higher values will appear simply as a chance to take a profit windfall and get out; and that in ten or fifteen years, after the bridge is completed, most of the community will not be the community that was there before the bridge - most of them will have left, for economic reasons (up or down).
But the real estate dealers and their politicos will still be there. It would not be surprising if their grandchildren propose a tunnel to the mainland.
Now, would any of this be O.K.??
Sure. The town on the Island should raise the bridge money with bonds pledged against property tax revenues and since the property values should go up after the bridge is completed, there should be greater property values from which to extract more property tax revenues with which to pay for the bonds. Any commercial bank worth its salt could analyze the situation and tell the town what the dividend rate the bonds would need to get them sold.
Meanwhile, a used-car salesman in Wisconsin would not be paying higher-than-otherwise-needed federal taxes so that these local yocals in Alaska can a have bridge.
Alaska has it backwards. First people gather, then build a town, then infrastructure as it is needed.
The "Bridge to Nowhere" is pork, rancid pork, on a large scale.
This kind of criminal plunder is typical of the pork in any bill that passes in Congress. And because all of our honorable representatives share in the swag there is no one to protect the taxpayers' interest.
There is more than enough money in such pork to completely re-build the entire Gulf Coast and have enough money left over to buy Brazil. And remember, the president almost always signs it into law.
To build a bridge because people might someday need it is, to say the least, poor planning.