I am saying precisely the opposite.
The numbers indicate that the Democrats do not require the Catholic vote while the Republicans do.
If you remove the entire Catholic electorate - Obama still wins in both 2008, and in 2012.
If you remove the entire Catholic electorate in 2004, Bush loses.
Ergo, I conclude that the Republican party now requires the support of Catholics in order to win. The Democrat party does not.
Why indeed, why do Catholics vote majority democrat?