Mark 12:35-37 and the present-tense Messiah

Mark 12:35-37New International Version (NIV)

Whose Son Is the Messiah?

35 While Jesus was teaching in the temple courts, he asked, “Why do the teachers of the law say that the Messiah is the son of David? 36 David himself, speaking by the Holy Spirit, declared:

“‘The Lord said to my Lord:
    “Sit at my right hand
until I put your enemies
    under your feet.”’[a]

37 David himself calls him ‘Lord.’ How then can he be his son?”

The large crowd listened to him with delight.

I read this text, and its synoptic parallels in Matthew 22 and Luke 20, and am startled by the presumption shared here between Jesus and his listeners. It sounds like that at least in one sense, nobody expected the Messiah to simply "ping" into existence, on the basis of another hopefully obvious assumption, that the "teachers of the law" were not teaching the people that the Messiah was already born/had already come. But, let us be thorough and spell this out: most of the teachers of the law that we know Jesus met, opposed Jesus (see Mark 2 for example, for the allegations of blasphemy, or simply earlier in the same chapter when they, along with "the chief priests" and "the elders" began to look for a way to kill him).

If the Messiah simply IS and not WILL BE, what could this mean? The pro-nicene trinitarians will insist of course that this corroborates their version of events, Jesus is co-eternal. It might, however, appear odd to them that the Messiah as a Jewish concept might be an eternal one.

In a second sense, we could say that this hope was alive and true in the hearts of all Jews, not that it would have been incorrect or surprising to say "how then will he be his son" or for the teachers of the law to have been teaching that the "Messiah will be the son of David", but that the tense consistently given in the synoptic tradition seems to portray a more adequate way of speaking about the reality of the living messianic promise from God himself.

In a third sense, and I think this might be perhaps truest to this pericope, we can also integrate some kind of pre-medical way of thinking about DNA! The Messiah has to be (note how this works in the present in English also) in the blood line of David.

Fourthly, we might remember that the whole issue of the tense, presently true or false, is actually on the table - see the rather curiously exegeted verses in 18-26 of the same chapter. God is the God of the living!

Fifthly, another possibility eases its way onto my horizon. What if the Messiah is not a single person? Like the King of Israel, or like Cyrus in Isaiah 45:1? This might help explain why Jesus has David talking to "him" a thousand years earlier and we can so happily jump through time and perspective (remember the teachers of the law's present tense). It does however fit less neatly with the parable of the vineyard, servants then finally: his son (singular), however see below on some quick problems with this rebuttal. 

How might a biblical Unitarian respond to such a text? I would actually really like to know if Samuel Clarke had anything to say about this passage.

But coming back to this a couple of days later... Jesus is expanding people's idea of the Messiah by making the Psalmist: David, quite possibly the correct interpretation but by NO means a straight forward choice.  Jesus is contrasting the presumed Messiah's (or messiahs') necessary human ancestry from David with the Messiah having apparently had Lordship over David.