The following is a hypothetical and I’m not claiming is what happened:
Assume that a Republican justice of SCOTUS thinks ACA (aka Obamacare), and specifically the individual mandate is unconstitutional, and so it’s best to have it struck down. But, he thinks, it could either be struck down by the court, or it could be repealed by a Republican controlled Congress and White House.
If he votes to uphold the law, and also upholds it by describing it as a new tax (a hated thing among conservatives that is sure to get them fired up to get up and vote), that could have the effect of getting people fired up to vote for Romney, who has promised to repeal the law. And if Romney gets elected, more conservative-friendly laws will pass.
So, on one hand, the justice could vote with the other conservatives in striking down Obamacare, with the possible effect of keeping Obama in office (since there is no longer this big specter of Obamacare that needs to be repealed, and conservatives are lukewarm about Romney anyway), which would go against advancing conservative ideals and positions.
And on the other hand, he could vote with the liberals and uphold the law (and make sure to uphold it as a new tax), with the possible effect of helping Romney win the election, which would in the long term help bring down Obamacare and advance other conservative ideals and positions.
Given the above hypothetical:
[li]Do you think that if Obamacare were struck down, Romney would have less of a chance of beating Obama this fall? (since one big motivator for voting for him would go away)[/li][li]Do you think a justice of SCOTUS would ever take such calculations into consideration?[/li][/ol]