It is probably no different than a labor union meeting where your support is expected in favor of the political party that primarily supports labor issues.
We often side with political parties because they support something we value, but usually not all of our values. As a result, we might find ourselves supporting other things or issues with which we disagree. Are we really caged to promote the whole set of items that a party has on their platform?
There is nothing wrong with convictions, but even spiritual expression differs within particular denominations. Labor union locals have their share of differences to the point of dissent, separations, merges, and even dissolution. The point is that we shouldn't sell ourselves short by toeing the party line when we disagree with it. There should be enough room to honestly engage with the important issues surrounding us without fear of political reprisal.
There is value in compromising with issues, candidates, or propositions, and being pragmatic. However, if we continue to compromise, we may soon find that those things that we once held valuable no longer have a chance of being defended or represented in a democracy. Ultimately those whom we elect may end up not representing our interests at all.
As an independent voter, one can speak freely, without the perceived pressure or obligation of a particular political party. Those who hear that voice should find comfort in a rough political arena, where one might feel homeless at times.