Assuming we are goning to treat this subject seriously, a couple questions have to be faced head-on:
- For what were the Chosen People chosen?
- Is/was Jesus the Messiah of the Chosen People?
If you discount that Jesus is/was the Messiah then nothing has changed and the Rabbinical Jews made the right choice and the idea that Christianity has any claim on being the new Chosen People is patently absurd.
If the Hebrews were chosen to bring forth the Messiah and Jesus is/was the Messiah then their task was done 2000 years ago and the Rabbinical sect, which took a wrong turn in history, has simply led the descendants of the Chosen People into the desert. In this case, there is no more Chosen People, Jews or Christians.
The more interesting possibility is that Jesus is the Messiah but that the Hebrews were chosen for something more. In that case, the fact that Rabbinical Jews are currently wandering in the desert doesn’t necessarily disinherit them.
I think this last is a real possibility because the OT does not merely point to the Jesus of the NT but to the centrality of Israel and Jerusalem to God’s plan. If the Jews have faltered in their role it would not be the first time and in the OT, God never gave up on his Chosen People.