According to CJ Roberts, the clerks have standing if they can claim a personal, particularized injury that they will suffer by issuing marriage licenses.
and if a clerk refuses to issue marriage licenses .... there will be consequences ...
if they can claim a personal, particularized injury that they will suffer by NOT issuing marriage licenses.
Maybe a county clerk would have standing, but this will probably come to a head another way. Some county clerk will refuse to perform a same-sex marriage, claiming that the Constitution of California prohibits him so to perform, and the issue likely will go before a state court. Given that a state court can’t rule that the constitutional amendment violates the state constitution, it would either have to (i) declare that same-sex marriage is illegal in CA, (ii) rule that Prop 8 violates the U.S. Constitution for some reason (whether for the reasons given by the gay district court judge (that any limitation of marriage to one man and one woman violates rational basis), the reasons espoused by Reinhardt in his vacated opinion (once a state permits same-sex marriage, it can never be taken away), or for some other reason (such as ruling it unconstitutional in this particular case because the referendum didn’t meet Kennedy’s new test from Windsor)), or (iii) declare that Prop 8 is no longer part of the California Constitution because it was struck down by the gay district court judge who wanted to marry his partner. Irrespective of what the state trial court decides, it would be appealed up the state court system until SCOCA rules one way or the other (but in any event it would result in Prop 8 being struck down), and then the county clerk would apply for cert from SCOTUS. And only then will SCOTUS decide whether the U.S. Constitution prohibits citizens of a state to amend their state constitution to limit marriage to one man and one woman. Unless, of course, by that time Californians have amendmed the state constitution again, this time to permit same-sex marriage, in which case the whole exercise would have become moot.