Some of my thoughts spurred by the question:
One might equally ask, can a Christian be a Republican? One might equally ask if a Christian can be a Baptist.
All human institutions have been corrupted. There are so many varieties and shades and sects, not to mention disreputable individuals in each group who contaminate the group by their mere presence, that one cannot even discuss "group", because the standards have all been undermined and polluted. One must then return to the original principles—purely interpreted. The Constitution is to be interpreted according to what it meant in the minds of the Founders at the time that they wrote it. So it is with the Word of God. Neither are "Living, Breathing documents that change with the times"—people corrupt them because people corrupt themselves and then want the stamp of approval of true authority upon their corruption.
A Christian must define himself by DOCTRINE (from the pure Word of God, not modern notions of what that Word means), not group affiliation; a Christian must define himself upon Anglo-Saxon Common Law (derived from the Bible) and upon the original US Constitution which is to be interpreted by the Common Law.
People tend to be egocentric and nostalgic. I, when I think of myself, think of myself as what I looked like when I was in my prime... (despite all my aches and pains and diminished strength)... when I walk past a mirror or a window reflection, I do a double-take, come back, stare, and say, "Who are you...? —and what did you do with ME...!" Needless to say, my body is not what it was when I was 27, 30 years ago. Had I remained a carpenter and athlete, it may have been closer, but such is not consonant with reality.
So it is with institutions. Republicanism is not what it was when Jefferson was around. The 'average' Baptist today, or Presbyterian, is not what the average was in 1920 or 1850 or 1700. To cling to memories is fond, but it is not reality. Thus, to not abandon altogether institutions and names that were righteously established on truth, prefixing adjectives must be added to the words, "Jeffersonian-Republican", for the average modern "republican" is in reality, "Socialist-lite". Even in Spurgeon's day and a century before, Baptists were being watered down with humanistic, Arminianist doctrine, and thus, those who held to sound doctrine referred to themselves as "Particular Baptists" or even "Strict Baptists", who held to Puritan / Reformed Doctrine. Particular referred to “Particular (limited, special, of the elect) Redemption” and Strict referred to “Strict (or closed) communion” and they were Calvinist Reformed Baptists. Most Calvinists today are not actually Calvinist. Calvin was not a Calvinist. Calvinism was named after Calvin died. However, people who call themselves 3 or 4 point Calvinists, are not Calvinist any more than "Christians" who deny the doctrine of the Word of God (in favor of humanism) are Christian. If you don't believe the main doctrinal, biblical points of Calvinism, you are not a Calvinist. Likewise, those who try to defame true Calvinists mindlessly call someone a "Hyper-Calvinist", but it is impossible to be "more Calvin" than Calvin; but such is their anti-intellectualism. Most Christians today are humanists who comfort themselves with the notion that they are Christian. They in their fallen mind, polluted by evil society and corrupt church of the 21st Century, read the Word of God and expect God to conform to man's corrupt notions of what is "good" or in man's mind, "fair to man". They don't understand the very concept of "GOD". They believe in a mythology like that of the ancients who created gods in their mind after their own image, with all their faults, foibles, feebleness, and failures. In reality, most are atheists. If they truly believed in God, they would not live as they do, they would not sin casually and flagrantly. They are idolators who do not believe in the true God, what they believe in is delusion and nonexistent, and therefore, they are atheists who deluded themselves into believing that they believe in God. The God of the Bible, the only God, is Immutable, Just, and Holy and will judge the world and judge each individual. To sin casually, thinking that God abolished His Law, or that "God is a God of LOVE, LOVE, LOVE, LOVE and His MERCY ENDURES FOREVER AND EVER and therefore He will never, never, never ever judge anyone" do not believe in God; and shall have a rude awakening when they stand naked before the Judge of the universe (going on a diet and doing a few situps really is not going to make matters any more bearable, turning from sin (doing what God forbade and not doing what He commanded), confessing it, asking for forgiveness through Christ's Sacrifice, and turning to what God commanded is the only thing that will remedy the situation. Works do not save; but if there is no change of behaviour, turning from what God forbade and turning to what He commanded, there is no repentance; only pseudo-spiritual delusion.
God is not a caricature penned in man's mind (like what I refer to as "Mr. Potato-Head Theology", "Smorgasbord Theology") in which man picks and chooses from God's Attributes (or Bible Doctrines) those that he likes and throws the rest away. God is undisectable truth: the Ultimate, Absolute full package. Tell me, how many tablespoons of a 12-oz. glass of orange juice can you remove and replace with sewer water, until the contents of the glass are no longer orange juice...? At what point would you decline to drink it? How many of God's Attributes can you chop off and throw away and still believe in the true God? How many Bible Doctrines can you jettison and still believe in the Bible? How many of Christ's Doctrines can you reject and still be a Christian? Rather than attempt to humanly reason the answers to such questions, would not the simple solution be to see how close to God you can approach, rather than how far away you can slink? Would it not be better to see how obedient and honorable you can be, rather than to see how disobedient you can be and yet not be rejected? Obedience / works do not save. They are the BY-PRODUCT of TRUE LIFE. If the words / obedience are not there, there is no true life. An tree does not become an apple tree by bearing apples; an apple tree bears apples because that is what its Creator decreed it to bear. Those that don't bear as they should, are cursed, whether a sterile apple tree or not an apple tree at all. So it is with sons. A man's offspring does not obey his father in order to become his father's child; he is the father's child by the will and act of the father in procreation. A child obeys his father to be an honorable son, whom the father will bless, and who will inherit of him. But Scripture says, if ye sin and be without chastisement from your Heavenly Father, then ye are not sons, but bastards — (illegitimate; not His sons). This is what examine yourself whether ye be in the faith, means; and work out your salvation in fear and trembling. The salvation in this verse does not refer to regeneration, which is 100% of God. It refers to walking in the Spirit, putting on the Mind of Christ, being certain that we are in Christ by looking into the mirror of God's Word and seeing if it reflect how we are living. Every tree is known by its fruit. Indeed, the flesh can produce counterfeit fruit, carnality masquerading as spirituality (as well as tares sown in among the wheat); however, while false fruit can mimic some qualities of true fruit, it cannot feign them all.
Obedience (whether wives to husbands, children to parents, servants to masters, man to God) is all or none. A servant / son / wife cannot "choose" which of the master's / father's / husbands laws he will obey. "Obeying" only what one wants to obey is not obedience; it is self-serving delusion: It is self doing what self wants, entertaining the delusion that it is obedience.
Contrary to the crass bumper-sticker / motto, "Sh*t happens!", not, it does NOT "just happen". Everything has a cause. Corruption in a family, a neighborhood, a church, a state, a nation, Christendom does not "just happen". As Edmund Burke, Anglo-Irish Christian Statesman expressed, "All that is required for evil to triumph over good is for good men to do nothing". But I posit, if good men do nothing in the face of evil, they are not really good. God declares, "to him that knoweth to do good and doeth it not to him it is sin" (James) and "whatsoever is not of faith* is sin" (Romans) and "have no fellowship with the unfruitful works of darkness but reprove [rebuke] them" (Ephesians). To not speak out and to not act when Christ would have spoken out and acted, is to deny Christ. Confessing or denying Christ is not mere verbal expression of a name—it is being a follower of Christ, not merely walking casually behind Him, but walking as He walked, as He commanded, as God commanded—obeying what He commanded; adopting His Mind and Will as your own; being offended when He is offended; His enemies becoming your enemies. To insult the father is to insult the son, if the son loves his father; to insult the husband is to insult the wife, if the wife loves her husband. To insult the master is to insult the servant if the servant loves his master. Modern notions of "independence" and "empowerment" are independence from and empowerment outside of God—which are humanistic myths that shall one day crash upon the rocks of reality. Christ, the Personification of Wisdom declared, "He that wrongeth Me sinneth against his own soul; all those who hate Me love death" (Proverbs).
[* Faith cometh by the facts [doctrine, theology] in the Word of God; not by personal opinions or “feelings”. True faith does not originate in man. It is the gift of the Holy Spirit whereby the elect believe. Faith is based upon the facts—the doctrine, of the Word of God. Like mathematical formulae, it is not man’s opinion of the facts, but the fixed, unchanging facts themselves that establish true faith as the Holy Spirit imparts the ability to believe, confess, and then—proportionally based upon true prayer, study, and meditation—understanding.]