I think you have to take the democrat party and break into the camps. There are progressive democrats and liberal (classical sense before progressives assumed that name) democrats.
You are correct to not trust any progressive...regardless of party. I have met those too and they scare me. Think of T. Roosevelt, W. Wilson, FDR, J. Carter, B. Obama and H. Clinton. They believe there is not a reason to fear a larger government because they are in control.
True liberals fear a large central government. Just a true conservatives fear a large central government.
You rarely find progressives occupying space with a state government because they believe the federal government is where they should be to get what they want done.
The unusual aspect of an article V versus the federal government attempting another constitutional amendment is that the states will not give the fed any more power today. They are in a literal stale mate.
Why do you think you saw an explosion of Amendments at the turn of the 20th Century but none sense? Because with what was gained during the progressive age, they have been able to re-shape this country into a similar European government.
Do you believe that state legislatures are looking to dump more of their limited authority on the federal government.
“Democrat... who is a defender of personal liberty.” Here is a recent example (only 1, too hard to find before dinner) of a democrat standing up for personal liberty with the NSA. Do they disagree on social programs. You bet, but on this issue the are of the same voice.
Although we might occasionally find common ground with someone like Connors, I don't trust for a second that he wouldn't immediately turn on us and drive the knife into the hilt.
Should we take every opportunity to try to turn classic liberals into Conservatives? Sure, but my experience is that they'll go with the Progressives when push comes to shove, often they are a lot more progressive than they put on and just acting the Old Democrat part to fit their constituency before moving up. Look at the Obamacare votes.