That simply isn't true even the most ultra conservative Catholics are only somewhat conservative, and it doesn't change the fact that republicans have won the Catholic vote 5 times in our history, and that the democrats have won the Protestant vote 3 times, 1932, 1936, and 1964 and Protestant isn't a single denomination but includes black churches and left wing Episcopalians, etc.
Look at this chart for 2004, even racially pure white Catholics, devout, church going still only went about 3% more republican than Protestant Hispanics, and about 24 points below their Evangelical counterparts, or even slightly less than the liberal mainline Protestant denominations.
