Abortion and homosexual marriage appear on the surface to be very difficult areas for classical liberalism to navigate. There are the twin shoals of excessive libertarianism and over-conservatism to avoid, for the question of government involvement in the matter is the central issue, and those who argue that government should not discriminate between normal and same-sex couples can make their case seem both principled and liberal-minded.
The truth is, however, that it is those who favor homosexual marriage and an abortion "right" who want to suppress freedom, and those who oppose these ideas are the ones who represent greater freedom.
Hence I argue that opposition to homosexual marriage and an abortion right are in fact the true classical liberal positions on these matters.
Classical liberals gravitate toward allowing communities to decide things for themselves, after Edmund Burke’s notion of the "little platoons," and we are intensely concerned with protecting both individual human lives and social order. As a result, I would suggest that classical liberals–such as Burke, Smith, Cleveland, Reagan, etc.—would unreservedly oppose legalization of abortion, unless it were proven conclusively that human life begins at some specifiable point after conception. Until then, a classical liberal would say, the law should unerringly protect the individual’s right to life, including from decisions by a child’s own mother.
In addition, the concern for federalism (aka subsidiarity) would make a true classical liberal unreservedly oppose the Roe v. Wade decision which took away the right of states—the people—to decide the matter.
As to same-sex marriage, classical liberals of the past would have thought the idea absurd. Imanging broaching such a question to Edmund Burke or Adam Smith!
Classical liberals would surely deny that there is any "right" to homosexual marriage. Rights are negative, not positive. That is, people have a right to be left alone by the government to do anything that does not harm others.
Applied to homosexual marriage, the argument following from this principle is clear: If homosexuals want to live together and get married in churches, they have an absolute right to do so, unless their way of doing so harms the community in some real and measurable way. But do they have a right to force others to acknowledge their choice? Absolutely not. The government has no right to force insurance companies, churches, schools, neighbors, etc., to acknowledge homosexual couples as marriages.
Why, then, does the government force these institutions to acknowledge heterosexual marriages? The answer is simple: It does not. These institution acknowledge heterosexual marriages on the basis of historical and cultural preferences developed over centuries. The government didn’t decide this; society did. In pursuit of social order, governments have required institutions to acknowledge marriage in their dealings with married couples (by creating marriage licenses, etc., with force of law), which from a classical liberal perspective makes sense as it did not infringe on individual liberties because people were already agreed that marriage was a valid institution. Moreover, even homosexuals agreed, and still agree, that marriage is a valid institution, which they confirm by trying to alter it so that their own couples can be included. The key factor is that the government, in acknowledging heterosexual marriage, does not force anything on the society, instead merely enforcing a contract that all or nearly all people accept as valid and sensible.
Homosexual marriage has no such status in society, as evidenced by the fact that it has little support in law nationwide and that nearly all of the moves to legalize it have come from the courts, not the democratic process. Hence, while the government has no call to prevent such marriages from occurring, it also has no valid authority to force individuals and organizations to acknowledge them.
If, for example, companies want to allow same-sex beneficiaries under their insurance plans, the government should not prevent them; and if insurance companies wish to allow such partnerships to count as marriages under their rules, they should be free do so; etc. And if they wish to exclude such partnerships, that is their right as well.
Homosexuals are already free to marry in America, they just aren’t free to force others to acknowledge those marriages. That seems a reasonable position at this time in human history and is most conducive to both liberty and social order.
That is the small-government position, the classical liberal approach.
Of course, proponents of heterosexual marriage argue that the same case could have been made against civil rights for blacks, and was in fact made. The difference, of course, is that the laws themselves discriminated against basic civil rights of blacks. In the case of homosexuals, the law allows them to marry and denies them only the ability to force other individuals and institutions to acknowledge their unions. That situation is extremely different from what blacks suffered under slavery and Jim Crow.
Hence the classical liberal position on this issue would be that it is a matter of choice, not right, as to whether society should choose to codify in law the position of forcing individuals and institutions to acknowledge homosexual unions. And as noted, the classical liberal position would be that forcing such a rule in most states and communities at this time is entirely unjustified.