The conservative argument for marriage equality

From Andrew Sullivan:

[I]t is conservative not to eject people from the fabric and tradition of their own families; it is conservative to support emotional and financial stability which the daily discipline of marriage fosters; it is conservative not to balkanize citizens into groups based on identity; it is conservative to discourage gay men and women from marrying straight men and women on false pretenses and then ending up in divorce; it is conservative to include everyone into the social institutions that stabilize society; it is conservative to promote mutual responsibility and care-giving to avoid too much dependence on government; it is conservative not to trample states rights and amend the federal constitution when such things are grotesquely unnecessary; it is conservative to adjust to social change by adapting existing institutions, like civil marriage, than inventing totally new and untested ones, like civil unions.