Republicans shoot selves in the foot
The Republican strategy of refusing to consider President Obama's Supreme Court nominee is ethically questionable and even more tactically questionable.
Obama has nominated Merrick Garland, described as a 63-year-old centrist appellate judge. Garland is well-regarded by members of both parties and would likely earn quick confirmation if this were not an election year, and a particularly toxic election year at that.
Most Republicans realize at this point that if the next president is not Hillary Clinton, it will likely be Donald Trump. A Clinton nominee would probably be more liberal and younger than Garland.
A Trump nominee might not be the kind of judge Republican senators want. Trump is not socially conservative, praising Planned Parenthood among other positions that are at odds with conservative orthodoxy.
In truth, no one can predict the kind of judge Trump would nominate. Republican senators, particularly Chuck Grassley, chairman of the judiciary committee, have no valid reason other than ill-conceived political posturing to reject the nominee without a hearing.