You gotta hand it to the Democrats, they're a lot more subtle about their corruption and malevolence. The Replublicans are comedically bad in contrast and it gives plenty of fuel to Democrats to claim that they're Different.
A good example is how Trumps taxes are viewed versus the blatant insider trading that the Democrats engage in.
You’re doing the thing. The Democrats are both: different in magnitude of corruption than Republicans, and absolutely imperfect and worthy of criticism.
For your example, 7 of the 10 congress members with the highest cap gains in 2024 (including the #1 spot) were Republicans. The previous democratic president and a significant number of Democratic members of congress support banning members of congress from trading stocks. The parties are not the same.