Re liberals having no coherent moral code, I invite you to read the article on John Stuart Mill in Wikipedia. His writings are the foundation of modern liberalism. Here's a pithy slice of his thinking which I subscribe strongly to:

John Stuart Mill’s religious view, influenced by John Locke, is that man is free to do anything unless he harms others. Individuals are rational enough to make decisions about their good being and choose any religion they want to. Government should interfere when it is for the protection of society. Mill explains, “The sole end for which mankind are warranted, individually or collectively, in interfering with the liberty of action of any of their number, is self-protection. That the only purpose for which power can be rightfully exercised over any member of a civilized community, against his will, is to prevent harm to others. His own good, either physical or moral, is not sufficient warrant. He cannot rightfully be compelled to do or forbear because it will be better for him to do so, because it will make him happier, because, in the opinion of others, to do so would be wise, or even right...The only part of the conduct of anyone, for which he is amenable to society, is that which concerns others. In the part which merely concerns him, his independence is, of right, absolute. Over himself, over his own body and mind, the individual is sovereign.”[6]

Mills also has a lot to say about the "tyranny of the majority"--which usually operates in regions where traditional American religion holds undisputed sway. I remember being subject to it. It is one of the hardest kinds of tyranny to escape because humans are social creatures, and social pressure is immensely powerful.

If religious traditionalists were willing to simply LEAVE PEOPLE ALONE, rather than always trying to impose their allegedly God-approved limitations on liberty on them, then I think most liberals would be happy to return the favor.