"Republicanism is a political philosophy, not a morality or theology."
The greatest Republican President of the last century would disagree with you that Republicanims is just about poliitics and not morality:
Hardly a day goes by that I’m not told—sometimes in letters and sometimes by people I meet—that they’re praying for me. It’s a warm but humbling feeling. Sometimes I answer when someone says that; I feel I have to say something. And I tell them that if they ever get a busy signal, it’s because I’m in there ahead of them. I grew up in a home where I was taught to believe in intercessory prayer. I know it’s those prayers, and millions like them, that are building high and strong this cathedral of freedom that we call America; those prayers, and millions like them, that will always keep our country secure and make her a force for good in these too troubled times. And that’s why as a nation we must embrace our faith, for as long as we endeavor to do good—and we must believe that will be always—we will find our strength, our hope, and our true happiness in prayer and in the Lord’s will.” —RONALD REAGAN
Will Rudy "endeavor to do good," when he won't even oppose infanticide, which is what PBA is?
Of course morality is inextricably intertwined with all we do. But to eliminate the practical political consequences of voting in a secular system of government in favor of purely moral principles serves neither politics nor morality.