Of course they have a bias. However, to use that bias to suggest things like the timing of decisions to coincide with Presidential elections (with the intent of making segments of the electorate angry enough to sweep your Party into office) is more than just being of the same judicial philosophy as your boss.
You can tell the real tale of a judge by who they have clerking for them. Its a better indicator that almost any other as to where they draw their support from and whom they are allegiant to.