I would be hard to convince of that, given that he was a lifelong cold-warrior. He also thought that the aggressive, anarchic, chaotic and strident anti-Americanism of the left was a serious threat to our national survival. That's not really a liberal outlook at all. Yes, he did the unexpected, after listening to Kissinger, I suspect, the inveterate jet-setter, was central to that; but he was closer to being a right-wing gangster than a liberal (IMHO).
Certainly not “liberal” by today’s standards -— but Nixon did all sorts of big government things -— the EPA being the worst mistake.