SCOTUSblog has this post on their analysis of the rates at which the Justices agree and disagree with each other, with particular attention to Justice Alito. Along with the numbers, the post includes this comment:
Still, one result that may give conservatives slight pause, and which liberals may see as a glimmer of hope, is the data regarding which conservatives Alito agrees with most frequently. Despite Alito’s being characterized as “Scalito” by some people during his nomination hearings due to what many thought to be strong similarities between the two, he has voted more consistently with Roberts and Kennedy than with Thomas and Scalia.
These "liberal" and "conservative" labels must be taken with at least a grain of salt, and maybe a heaping tablespoon. In United States v. Gonzalez-Lopez, Justice Scalia wrote the opinion favoring the defendant, while Justice Alito wrote the dissent favoring the prosecution, joined by Chief Justice Roberts, Justice Kennedy, and Justice Thomas.
Should "conservatives," generally regarded to be on the prosecution side in simplistic analyses, be given "pause" by the fact that Justice Alito agreed with Chief Justice Roberts and Justice Kennedy rather than Justice Scalia in this case? I don't see why.