I am a centrist. I pick the party that has the most viable place for centrists. I have voted for and registered as a Republican in the past. Lately, though, I find the Democratic Party is the only viable home for a centrist. The Democratic Party is a bigger tent. The Republican Party is prone to purges designed to drive out the ideologically impure, including centrists who want to work with the other party to govern.
The Republican Party was born of establishment white Protestantism, which remains the core Republican constituency today. I am an establishment white Protestant. Most members of my church, the mainline Presbyterian Church (U.S.A.), are Republicans. The great strength of the historic core of the Republican Party has been fiscal responsibility and a strong military to build up good order in society. I believe American politics works best when one party holds up this side of government, in constant dialogue with the party of helping people in need and defending the weak for the compassionate order of society.
Sometimes, though these Republican virtues get pulled, by anger and fear, to a bad extreme. Fiscal responsibility becomes "only spend money on me"; a strong military becomes "use any force on anyone who might threaten me"; build up the good order of society becomes "prevent government". Worse, establishment white Protestantism has a tendency, when fearful, to become an angry nativism that turns harshly against immigrants and imagined conspiracies by foreign ideologies.
The precursor to the Republican Party was the Whig Party. It had the same core and, at its best, the same strengths. The Know Nothing movement tore apart the Whig Party. The Know Nothings lasted only a few years, and produced no legislative achievements. Today the Tea Party movement occupies the same position in relation to the Republican Party. I do not think the Republican Party will be torn apart, as the Whigs were. But I do think that the current nativist tempest will subside, the fear and anger will recede to the wings.
I look forward to the return of the traditional Republican Party as a partner with the Democratic Party in good government.