I think they'd argue that they have a consistently liberal "bias" in all subjects, it's just they don't map cleanly onto modern left-right politics. For example they favor deregulation and privatization which are traditional "right wing" stances, while also favoring gay marriage and drug legalization which is an issues that has recently been more championed by the left. The Economist would argue that their stance in both issues is "liberal" thus there being no contradiction.
