As a matter of caution, do not initiate political subjects and conversations, and when your boss does, from time to time point out that liberalism and conservatism are both valid political philosophies.
Liberalism is based to a large degree on benevolent feelings toward others and a desire to help them. This is commendable and makes liberalism especially appealing to the helping professions -- nursing, teaching, social work, and so on. Some major advances in American life have come at the urging of liberals.
Conservatism is also benevolent, but it is based not on feelings, but on hard facts that limit what good can be done in the world. Resources are limited, people tend to be self-interested and are sometimes mean, destructive, or evil, and adopting bad laws and policies can squander resources, destroy social trust, erode important institutions, and even wreck entire countries.
Liberals aim to make major changes that improve the lot of others and make a better and more just society. Conservatives prefer to assure that the good things be preserved, and that they run properly and improve incrementally. We do best by permitting both philosophies to be expressed and to pick and choose the best they have to offer on the merits.
In the American context, conservatives aim to preserve the freedoms and opportunities that America offers, which are based on our constitutional system, the bill of rights, the rule of law, and on traditional virtues.
Note also that, despite what liberals may think, conservatives are not hard-hearted or unsympathetic to others. Studies repeatedly show that conservatives give more in charitable donations and volunteer more for charitable work than liberals.
Why? Again, conservatism is a philosophy based not on grand feelings and gestures but on facts and small, practical steps.
If political conservations get too risky or tedious, one approach is to shut them down by diminishing their appeal. Do some internet research on your boss's favorite issues. Have an article or two from National Review or the Weekly Standard or some other good source at the ready, and, when pressed on an issue, offer it as an explanation of your views.
Liberals are usually flummoxed by having to deal with well stated, written refutations of their views. A few doses of that tends to curb their appetite for political gabbing. There is nothing more deflating to generous, liberal feelings than repeated doses of hard facts.
Then I point out that our society evolves through ideas. If we all have the same ideas then we are like some bird that can only eat one type of plant seed. Fine as long as there are plenty of seeds, extinct if it doesn't work out.
Society is similar, we need a range of ideas and viewpoints so that we don't get trapped by the wrong ones.
That usually silences them, and gives them something useful to think about. Few of them realize that their entire philosophy depends on their ideas being right, and that it will and does fail miserably because nobody can make the right decisions and manage society. That's what free markets are for.