Yet they still block every single gun control measure that comes up.

That's not quite true: they selectively block gun control measures. For example: they put through the Mulford Act, a gun control measure, because black activists started arming themselves.

Named after Republican assemblyman Don Mulford and signed into law by governor of California Ronald Reagan, the bill was crafted with the goal of disarming members of the Black Panther Party, which was conducting armed patrols of Oakland neighborhoods in what would later be termed copwatching.

Both Republicans and Democrats in California supported increased gun control, as did the National Rifle Association of America.

They're less "pro-gun" and more "we should have guns", and I think that difference is important to emphasize in liberal society.