That is their strength. They are incredibly devoted to their leftist ideas. Every time there is an opening they squeeze in. Many conservatives on the other hand seem to not have a plan. They just assume all the good from the good old days will continue on its own. Not true since the plan of the leftists is to continually wear it down and before we realize it, they have worn away the good and their numerous crazy ideas become mainstream. I won't list them since we talk about them all the time.
How do we proceed? Use the leftist tactics. Have a plan and execute it at every opening. Too bad few of our politicians have no plan. They aren't conservatives in their hearts. They are afraid to push back against leftism, so they let them have their way.
That is their strength. I'm not sure conservative don't have a plan, rather that they don't act in unison like the left. Irrespective of individual issues. Not sure that's a weakness, though it can be in the short run.