I think the Abrahamic covenant was fulfilled in Christ, the Mosaic covenant was forfeited through disobedience, the Davidic covenant was kept in Christ (perpetual reign of David's descendent) but forfeited as well (the line of kingship appeared broken and the land was lost). When the Jewish leaders and large portions of the populous rejected Christ, they rejected their God in the flesh, the fulfillment of their scriptures, the hope of their messianic salvation. Those who believed in Christ inherited the blessings, and God opened those blessings to the Gentiles through Christ as branches grafted in. Salvation and blessing are still available to the Israelites, just as they are to the Gentiles, through salvation in Jesus Christ. That's what I've come to believe anyway.