If we live a worldly life, then I think we have some responsibility to engage in worldly issues. While the Buddha clearly discouraged the monastic community from engaging in worldly activities such as politics, I think it's a mistake for lay-followers not to be. For one, politics affects almost every aspect of our lives, and being engaged in our communities and being a part of the political discussion, not to mention being active in broader social and political movements, is what makes our society and political systems function more effectively, and how progress, however slow it may sometimes be, is made.
To leave these kinds of activities and decisions solely in the hands of others, some of whom are slaves to their defilements, isn't wise, in my opinion. And if we choose to live in the world, then I think we share some responsibility for shaping it; and it makes sense to have people motivated by things like non-greed, non-aversion, and non-delusion add their voices to the mix, not to mention helping do what they can to fix things like inequality and injustice as long as it's done with a spirit of compassion and harmlessness. The greatest danger of the practice of renunciation, in my opinion, is the tendency of practitioners to ignore the world around them while seeking their own happiness. All too often, Buddhists fall back on teachings like all conditioned things are inconstant, unsatisfactory, and not-self (
AN 3.134) while neglecting teachings such as 'I am the owner of my actions, heir to my actions, born of my actions, related through my actions, and have my actions as my arbitrator. Whatever I do, for good or for evil, to that will I fall heir' (
AN 5.57).
Moreover, just from a practical standpoint, not addressing many of the material conditions giving rise to and supporting society's suffering ultimately serves to help maintain their continued existence (when this is, that is), which can negatively affect our practice, as well as that of others. If the society one lives in isn't conducive to practicing Buddhism, for example, then it does matter what kind of society one lives, so we should naturally try to make it as conducive for ourselves and others as possible. As the Buddha said in
Khp 5, "To reside in a suitable locality, to have done meritorious actions in the past and to set oneself in the right course — this is the greatest blessing." To help illustrate what I mean here, I'll give two example.
A general example is that a society that's not only consumerist, but also politically and economically geared more towards the idea that greed and self-interest is the highest good, will potentially be less supportive culturally of monastic communities that live entirely in an economy of gifts (e.g., in comparing Eastern cultures, in which alms-giving and gift exchanges characteristic of 'human economies' regulated by custom and reputation and based more on co-operation have historically been more prevalent, to Western culture, where market-based economies based more on competition have been the norm, I noticed that Eastern monastics often receive more lay support as opposed to Western monastics, who often have to produce goods like beer, chocolate, coffee, wine, etc. to sell in order to support themselves).
A more specific example is the ecological impacts of logging in Thailand. The Buddha praised the wilderness and the benefits of practicing in the forest. The Thai Forest tradition grew out of a movement among monastics to return to this way of practice. In the past few decades, however, much of Thailand's forests have disappeared, making this more difficult. Being involved in conservation efforts and trying to find better farming techniques and/or other ways of raising revenue is one way of trying to help preserve remaining forests in order to help keep this tradition alive.
It'd be great if everyone were free from greed, hatred, and delusion, and everyone treated everyone else with kindness, compassion, and generosity—if the world was free from all forms of exploitation, privation, and gross inequalities. But the world isn't a perfect place, and we're not all saints; and one of the ways we can help alleviate some of the world's suffering is by trying to materially change it for the better. And from this point of view, it's not about making Buddhism political, but about applying the ideals of Buddhism in all that we do, which for me includes being socially and politically active.