Evil Conservatives -- Hacks and Ideologues
The question is why do so many evil conservatives exist? Although I wouldn't normally use the term "evil" to describe any conservative. The term will do for this post.
There are of course two answers -- as is the case with most difficult questions. The first answer is political hackery. By that, I mean the pursuit of political power. Political hacks want political power and they are willing to compromise principle to obtain it. The second answer is political ideology. Political ideologues are so blinded by their single issue that they are willing to step on people and process to prevail on their single issue - the "ends justify the mean" syndrome.
Political hacks can come in different flavors -- non-ideologues or "moderates" and ideologues called "conservatives" or "liberals." So often our politicians are becoming conservatives or liberals -- rather than merely being politicians.
I believe that political hackery and political ideology are the principal obstacles to any political party's success. The extent a party succeeds will be directly related to how many good, principled people get involved and how long they work to rid their party of political hacks and political ideologues. It is the only sure path to electoral success. But, even if there is success, the minute the good people leave or quit working the hacks and ideologues return.
Perhaps, the brilliance of the two-party system rests on this notion. That no party can perpetually retain enough good, principled people to beat back the party hacks and ideologues permanently. So, a political cycle is created where the prevailing party will eventually destroy itself giving opporunity to the minority party.