This answer is really reflective of my own personal opinions, just as the other answers below show other's opinions too. Really there is no right answer to this question. To some liberalism reflects their own morals, to others liberalism is against their morals.
Either side of the line, liberalism and conservatism, are both morally right, though we may agree with one side's values more than the other's.
Yes, I do believe that liberalism is morally right. Liberalism promotes the idea that every one should be treated equally, which I think is the most important moral to be preaching. Liberalism also preaches equality when it comes to marriage, and marriage can be viewed by some as being morally right.
Liberalism is a morally right stance because it is all about progressing and giving the best circumstances to the communities we live in. Conservatism is about staying in the past for the sole purpose of tradition and benefiting those who are already in power. Liberalism is the morally correct point of view.
Liberalism is a vague term but over all represents morality much better than conservatism. Conservatives are for life no matter what, even if it is a zygote that has just began cellular division. It is amorally wrong to force a woman to bring this fetus to full term when they were raped and have to live with that every day.
The main detractor to liberalism will be conservatives who believe that gay marriage or abortion are mortal sins. That's a fair opinion, but it does not mean liberals are immoral. The term "moral" is quite subjective. I, being a liberal, believe that my views are quite moral. I believe in equality for everyone. Gays, lesbians, bi-sexuals, black people, white people, Asian people, poor people, and even rich people. We believe that everyone is created equal. We fought for the right to vote for women and for the civil rights act, which gave millions of people the right to vote (and not be 3/5s a vote). It's called progress. This is not to say that Republicans are immoral or evil. They're simply doing what they think is right. I think history will show them to be wrong, but I certainly don't think they're evil or immoral.
As a strong conservative, I disagree with the stances that most liberals take... So I see liberalism as morally wrong, but liberals see their stances as moral and mine as immoral. The position they usually take is about tolerance and what is easiest, not what is necessarily best for our country. So they sometimes ignore what they know is right and choose to back what is wrong.
They aim for equality and respect in a tolerant society, which is a good thing. However, they do so by being intolerant, abusing anyone who doesn't agree with them. They cause a ruckus whenever something doesn't go their way, and when offended, they use derogatory and discriminatory terms. They aren't any better than who they call 'evil'. As you can see from some of the arguments for yes, they are slandering conservatives and others. Practice what you preach and listening to others' point of view.
I am a liberal but do not consider myself morally right. Liberalism and conservatism are beliefs based on one's circumstances and beliefs, two highly subjective things. There are some conservatives who act with a strong moral compass and some conservatives who appear to have no morals at all. The same is true for liberals. Morality doesn't decide political views, your life's experiences and attitude do.