This is the misconception you right wingers all have. It's because you've been brainwashed by FOX NEWS to believe it.
Judges, all judges, regardless of which side of the isle appoints them are dutifuly sworn to abide by the U.S Constitution. PERIOD
They are Apolitical, meaning not political, nor will it ever cross their minds, that since R or D appointed me, that's where my decision will go.
You don't have enough fingers and toes on the number of times that a Justice has gone against the party or President that has appointed them.
And like politicians, many judges could give a shit about the oath they took. If judges used the same standards, split decisions would be the exception and not the rule. Also you wouldn't be able to predict how a judge would vote. Rarely are there any surprise votes coming out of the supremes, they're totally predictable.
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You mean like John Roberts--(a G.W. Bush appointee) that was the deciding vote on Obamacare--

There are always surprises coming out of the U.S. Supreme Court.
And if you think you got a couple of Anthony Scalia's in Justice Niel Gorsuch & Brett Kavanaugh--you're barking up the wrong tree.
Gorsuch & Kavanaugh both came out of the gate as GW's nominee's to Federal District court of Appeals in 2006. In 2006 Democrats were the majority in the Senate. While Democrats turned down a lot of G.W.'s nominees, these two came through that gauntlet with flying colors.
All of the above voted for confirmation of Gorsuch & Kavanaugh. The only reason Democrats tried to block Gorsuch, is because they were pissed that Republicans blocked Obama's nominee, Merrick Garland from an up or down vote. The only reason Republicans blocked Garland was so they could campaign on the next Supreme Court justice--(because you never know who Hillary Clinton would have picked)--
Niel Gorsuch is the only nominee in my memory that stated during confirmation hearings, that Roe v Wade is precedent in the constitution, meaning set in stone to you.
Gorsuch to Feinstein: Abortion ruling is 'precedent'
So don't be surprised--and it's because they have sworn an oath to the U.S. Constitution,
not a political party.