Is MMT a left-wing or right-wing idea?

MMT is neither left-wing nor right-wing - it's a description of how modern monetary systems actually operate. Like learning how an engine works, understanding MMT doesn't tell you where to drive.

MMT economists tend to be politically progressive and often advocate for policies like the job guarantee, Medicare for All, or the Green New Deal. But this is because they believe these are good policies, not because MMT requires them.

A conservative could accept MMT's description of how money works while advocating for tax cuts, smaller government, or different priorities than MMT economists typically support. Warren Mosler, one of the founders of MMT, has proposed eliminating payroll taxes and corporate taxes - not typically 'left' positions.

What MMT does is remove false constraints from policy debates. Once you understand that 'how will we pay for it?' is the wrong question for a currency-issuing government, you can debate policies on their actual merits - their effects on inflation, employment, inequality, and real resources.

Some critics from the left worry that MMT lets governments off the hook for taxing the wealthy ('we don't need their money'). Some critics from the right worry it justifies unlimited government spending. Both critiques miss that MMT is about understanding reality, not advocating specific policies. What you do with that understanding is a separate question.