The league has just gotten to the most interesting stage and for sure we can point to the dominating team for this season just as you have said Rangers and Celtics are topping the table and for sure Rangers seem to have more chances of winning this season despite occupying the second position currently, the reason is that the last two games happen to be their worst games this season and the reason why there still at the second position and looking at Celtic few next matches you will notice that are up against clubs that can drop them from the top of the table if care is not taken.
I don't get the logic behind you rooting for Rangers to win the Scottish premiership this season even after being 16 points clear behind the league leaders Celtic who have put of their better performance gotten that far in the league with 29 matches already played and just 9 more to end the season. 
If you assume Celtic might drop points then what makes you think Rangers wouldn't as well drop points against some of their opponents in the 9 games left to rap up the season. It's obvious Celtic has conquered this season and rangers should strive on maintaining their second position that Hibernian or Aberdeen not dispose them before end of season.