This is a good point but only goes half the way there. The problem is that Democrats who know better seldom publicly push back on the fifth bad idea for fear of the fringier elements of their coalition. This enables the right wing propaganda machine to portray it as the position of mainstream Democrats. Until a Democrat with guts comes forward to call BS on BS, we’ll never overcome this problem. The Republicans actually suffered from the same problem with regard to the Iraq war until Trump finally did so, cutting through the Republican BS on that (“George W kept us safe”) but unfortunately replacing it with his own.