In Fourth Amendment cases, it's a toss-up

A lot of people think that today's Supreme Court is conservative and pro-government in Fourth Amendment cases. It can be hard to analyze those views because they often hinge on disputed questions of framing: What is the baseline for determining what the Fourth Amendment should be interpreted to mean, in order to say whether the Court tends to be "pro government" or "pro defense"? With that said, one very blunt measure is to count wins in argued cases. The Supreme Court usually grants cert and hears argument in cases only when there was a division in the lower courts about how the law applies. The Court then hears the case and picks a side, effectively moving the law in one direction or the other. Given that, we can get a very rough cut answer to the question by counting wins in recent argued Fourth Amendment cases.

If you look at the argued cases decided in the last three Terms, the results are evenly divided. Out of eleven cases, the government has won six:

Heien v. North Carolina (2014)
Plumhoff v. Rickard (2014)
Navarette v. California (2014)
Fernandez v. California (2014)
Maryland v. King (2013)
Florida v. Harris (2013)

On the other hand, the individual challenging the government has won five:

Rodriguez v. United States (2015)
Riley v. California (2014)
Missouri v. McNeely (2013)
Florida v. Jardines (2013)
Bailey v. United States (2013)

As I said, this is just a rough cut. Some cases are more significant than others. And different people will have different views about what the baseline should be. Still, it's an interesting result. When it comes to the Fourth Amendment, today's Supreme Court isn't as one-sided as some people seem to think. If you learn that the Supreme Court has agreed to hear a new Fourth Amendment case, that fact alone gives you no hints about how the Court might come out. Every Fourth Amendment case is different, and the votes will go where they go depending on the case.