Nah, it happens on both sides, you're just not noticing it because of your bias. Perhaps it's more subtle on the liberal side. The liberal caucus, by its nature, has much more room for internal dissent. Take the race for President -- a lot of the language is put in terms like do you want a idealogue, or someone who is more electable towards the center. But of course, there's not so much evidence that the relatively centrist candidates are more electable.
Obamacare, for instance, was a major attempt by Obama to reach across the aisle and get conservatives to help on health care. It was a market-based solution based almost entirely on Romneycare in Massachusetts. The party activists were calling for a public option, or maybe single-payer like Medicare, or even a few at the far left calling for a government takeover like the National Health Service in the UK. But Obama reached fairly far from liberal ideology to get conservative support for the ACA, it's just that we now have so little in common that conservatives saw it as an utter betrayal than an attempt to cooperate.
Obamacare, for instance, was a major attempt by Obama to reach across the aisle and get conservatives to help on health care. It was a market-based solution based almost entirely on Romneycare in Massachusetts. The party activists were calling for a public option, or maybe single-payer like Medicare, or even a few at the far left calling for a government takeover like the National Health Service in the UK. But Obama reached fairly far from liberal ideology to get conservative support for the ACA, it's just that we now have so little in common that conservatives saw it as an utter betrayal than an attempt to cooperate.
"Kitto daijoubu da yo." - Sakura Kinomoto