I would encourage opposing views on this site, however, I don't see anyone really able to defend a Democrat position, or policy with anything but emotion, and name calling.
You're right, so I find it useful to do it myself. I'm willing to change my position if I find that it's outdated, incorrect, or harmful. Not only in politics but in my work and other activities.
Being unable to find a democrat who can defend their position without resorting to "well you follow the mango poopyhead" (which is where I stop listening / reading), I went over to democrats.org to see just what their positions are and try to come up with reasons to support them.
I was surprised to see that many of their positions are already being addressed by the Trump administration:
RAISE INCOMES AND RESTORE ECONOMIC SECURITY FOR THE MIDDLE CLASS
Raising Workers’ Wages
Protecting Workers’ Fundamental Rights
Supporting Working Families
Helping More Workers Share in Near-Record Corporate Profits
Expanding Access to Affordable Housing and Homeownership
Protecting and Expanding Social Security (doing that with higher wages and more workers)
Ensuring a Secure and Dignified Retirement (having a job is a good thing)
Revitalizing Our Nation’s Postal Service (OK, not that. Why would we want to do this?)
Many other issues I can agree with. What I don't agree with is how they intend to implement their strategy. Their strategy is either bigger government or taking from one group and giving to another. "Build a 21st century infrastructure." Great. Sounds good. Let's do that. But how they want to do it sucks: "Democrats will also create an independent, national infrastructure bank that will support critical infrastructure improvements." Yeah, no chance for corruption and waste there.
Other issues I flat out disagree with. For example, "making the wealthy pay their fair share of taxes". They are already paying virtually all of the taxes. And democrats never define what is their "fair share".
The point I'm making here is that we can't depend on the democrats to present and defend their own ideas. For the most part, they are not able to either because they lack the intellectual horsepower to do so or their positions cannot be defended. But we do ourselves a disservice to live in an echo chamber. Exploring and analyzing alternate ideas is a good thing. It's often uncomfortable and it requires work, but the result is a more thorough understanding of the other side, a stronger defense of the issues we want to defend, and perhaps some modification of existing ideas to something better.