How would the US be different today if people coming off the boat were greeted with a welfare check instead of a shovel?

Politics is a romantic search for the good and the true and the beautiful.

Politicians and bureaucrats are no different from the rest of us. They will maximize their incentives just like everybody else.

How would the US be different today if people coming off the boat were greeted with a welfare check instead of a shovel?

America is perhaps excessively mobile in the sense that there is sometimes not enough stability in communities. Dynamism in the economy is not necessarily the "be all and end all".

If politicians get money to spend and don't have to be responsible for taxation, then of course that will bias their attitude toward more spending as opposed to cutting back on spending.

Once you have an equalization instrument in place, as you have in Canada, there arise tremendous bureaucratic values - bureaucratic rent so to speak - in maintaining the system that you have. To shift to a system that paid the transfers directly to individuals, by having differential rates of federal income tax levied to adjust to provincial fiscal capacities, which would be my preference, you would have huge bureaucratic opposition. People would try to protect the rents they have in the current system of institutions.