This is probably a little confusing because in the United States “liberal” often means “on the political left,” but that’s not what it means to political philosophers, political scientists, and in much of the rest of the world. (In the same way “democrat” can just mean someone who supports democracy, not necessarily a member of the U.S. Democratic Party.).

In the broad political philosophy sense, “liberal values” means things like human rights, free speech & press, democratic government, religious toleration, freedom of trade & movement, etc. In other words, the values of liberal democracies like the United States. It doesn’t mean “the values of the people who are called liberals in the context of U.S. politics, where liberal is understood as contrasting with conservative.”