You’re describing this as tailism but I think it is flipped around actually. Rather than try to strategically adopt right wing positions, socdem electoralists actually want to do the right wing policies while claiming (moderated) left positions. Their strategy is one of cooption of the left while inevitably catering to the bourgeois state interests of the office and their perceived ability to stay in office (especially the careerists surrounding the “elected”). They do moderate when liberals push them, which is a tailist tendency, but that isn’t what they would actually prefer to do. They’d prefer to say, “abolish the police!” and then have 30 excuses for why they couldn’t. Then tell you thay you gotta really put effort into their next election campaign and then it might happen.

In terms of a plan, I gotta level with you, the plan is to get and stay elected. Everything else is secondary. They will likely jettison just about anything that gets in the way of that. This is because they face immense pressure and both personal and organizational material interests to stay in office and play ball with the bourgeois state apparatus. Internal organizational discipline could counteract this, but accordingly electoral formations reject and actively push back on organizational discipline because it is directly against their interests. And in this case the DSA is utterly undisciplined to begin with (and does not have a larger on the ground organizational base to rely on), so it all comes down to whether just one guy, Mamdani, decides to stick his neck out.