"No, let me correct that. They agree—more or less—on a lot of general principles, but all too many liberals tend to be "one-issue" oriented and have difficulty making common cause with other liberals unless their issue is the paramount one. "

Good point. Perhaps this is what causes what I see as self-destructive behaviour- When one group does not give the priority to a specific point that another group thinks it deserves, the two groups end up fighting each other rather than looking for commnon ground.

As for "How can one fail to "toe the party line" if the main problem liberals have is that there is no "party line?" "

I think you mena how can one "toe the line..."- Correct me if I am wrong. In the case above, there are as many "party" lines as there are issues, each one of paramont importance to some group with ihe party. Thus, ANY deviation from the TOTAL of the "party lines" is cause for "vituperation", as Cohen says- and whichever group that issue was important to will feel that the apostate viewpoint is unacceptable.

It seems to me that this can only lead to fragmentation , and the continued ( since all other points can't be discussed without upsetting someone) running AGAINST the conservatives, rather than presenting a group of viable goals ( that all would have to agree to) and a path to accomplish them to the electorate, and running FOR something.

IMHO, of course.