In the 19th century, immigrants were voting for Jefferson's laissez faire Democrats, natives for Hamilton/Lincoln's proto-progressive GOP.
[TABLE="class: wikitable"]
[TR]
[TH="colspan: 3"][/TH]
[/TR]
[TR]
[TH]
Religion[/TH]
[TH] % Dem[/TH]
[TH] % Rep[/TH]
[/TR]
[TR]
[TH="colspan: 3"]Immigrants[/TH]
[/TR]
[TR]
[TD]
Irish Catholics
[/TD]
[TD]80[/TD]
[TD]20[/TD]
[/TR]
[TR]
[TD]All
Catholics[/TD]
[TD]70[/TD]
[TD]30[/TD]
[/TR]
[TR]
[TD]Confessional German Lutherans[/TD]
[TD]65[/TD]
[TD]35[/TD]
[/TR]
[TR]
[TD]
German Reformed[/TD]
[TD]60[/TD]
[TD]40[/TD]
[/TR]
[TR]
[TD]French Canadian Catholics
[/TD]
[TD]50[/TD]
[TD]50[/TD]
[/TR]
[TR]
[TD]Less Confessional German
Lutherans
[/TD]
[TD]45[/TD]
[TD]55[/TD]
[/TR]
[TR]
[TD]
English Canadians[/TD]
[TD]40[/TD]
[TD]60[/TD]
[/TR]
[TR]
[TD]British Stock
[/TD]
[TD]35[/TD]
[TD]65[/TD]
[/TR]
[TR]
[TD]
German Sectarians
[/TD]
[TD]30[/TD]
[TD]70[/TD]
[/TR]
[TR]
[TD]
Norwegian Lutherans[/TD]
[TD]20[/TD]
[TD]80[/TD]
[/TR]
[TR]
[TD]
Swedish Lutherans[/TD]
[TD]15[/TD]
[TD]85[/TD]
[/TR]
[TR]
[TD]
Haugean Norwegians[/TD]
[TD]5[/TD]
[TD]95[/TD]
[/TR]
[TR]
[TH="colspan: 3"]Natives[/TH]
[/TR]
[TR]
[TD="colspan: 3, align: center"]Northern Stock[/TD]
[/TR]
[TR]
[TD]Quakers[/TD]
[TD]5[/TD]
[TD]95[/TD]
[/TR]
[TR]
[TD]
Free Will Baptists[/TD]
[TD]20[/TD]
[TD]80[/TD]
[/TR]
[TR]
[TD]
Congregational[/TD]
[TD]25[/TD]
[TD]75[/TD]
[/TR]
[TR]
[TD]
Methodists[/TD]
[TD]25[/TD]
[TD]75[/TD]
[/TR]
[TR]
[TD]Regular Baptists[/TD]
[TD]35[/TD]
[TD]65[/TD]
[/TR]
[TR]
[TD]Blacks[/TD]
[TD]40[/TD]
[TD]60[/TD]
[/TR]
[TR]
[TD]
Presbyterians[/TD]
[TD]40[/TD]
[TD]60[/TD]
[/TR]
[TR]
[TD]
Episcopalians[/TD]
[TD]45[/TD]
[TD]55[/TD]
[/TR]
[TR]
[TD="colspan: 3, align: center"]Southern Stock[/TD]
[/TR]
[TR]
[TD]
Disciples[/TD]
[TD]50[/TD]
[TD]50[/TD]
[/TR]
[TR]
[TD]Presbyterians[/TD]
[TD]70[/TD]
[TD]30[/TD]
[/TR]
[TR]
[TD]Baptists[/TD]
[TD]75[/TD]
[TD]25
[/TD]
[/TR]
[TR]
[TD]
Methodists[/TD]
[TD]90[/TD]
[TD]10[/TD]
[/TR]
[/TABLE]
Source: Paul Kleppner, The Third Electoral System 1853-1892
(1979) p. 182
It changed in the 20th century, of course, with the Jeffersonians being pushed out and the Dems adopting the progressivism of the GOP. From that time forward, they were quite similar, fighting over power rather than ideology. The 16th Amendment was proposed by a Republican President and passed by a Republican Senate and a Republican House. The Federal Reserve Act was passed with broad bipartisan support in the House and Senate (and was really just a rehashed version of GOP Senator Nelson Aldrich's plan from a few years earlier - what Republican opposition there was to the bill was based on wanting the bank to be
less accountable to Congress). Both income tax and a central bank had been part of the GOP platform from the beginning of the party, in any event. Hoover was as bad as FDR (just not as good at winning elections), FDR's psychotic relative Teddy was as bad as Wilson. No one has anything to brag about in the 20th century.
The theory that the US was originally inhabited by liberty lovers, who were corrupted by immigrants simply doesn't correspond to reality. A better, short account of US history might go as follows: In the beginning, there were nutjobs in New England, and rational Whiggish people in the South. Then immigrants arrived and sided with the South. But by about 1900 the nutjobs outmaneuvered and converted the others, the original Southerners and the immigrants, and now everyone's a nutjob. Of course, behind the ideology of the nutjobs is a great deal of self-interest, from boodle-seekers, which would have ultimately expressed itself in a growing state regardless. So, in that sense, the nutjobs don't really matter, things would have played out about the same anyway, but if you want to blame anyone for corrupting the American liberal tradition, you should blame that faction of natives known as Yankees, not immigrants.