It's the Overton window. If the right ideas keep losing, then the left ideas have more say. If the right wing ideas don't win you elections, they slowly fade away. If left wing ideas win you elections, the the whole Overton window goes to which left wing ideas will win.
Like dude you just listed off the entire Overton window that they're appealing to because it won them an election and might win them another election. Like you just did it! Why do those talking points even exist? Because it won and could win again. Shut those out by voting. Tell them resoundingly that there's no chance of winning on those ideas, and then the Overton window can move left.