Always attack the left from the left and the right from the right. I only really know American politics well but I'm sure there are good examples from each country:

For leftists: point out endless wars that torment & kill the poorest minority children all over the planet. The blatant, rampant, and unapologetic corruption. The fact that regulation screws over regular people by making everything way too expensive, especially in the housing market.

For right wingers: the ridiculous spending. The fact that Social Security is a government funded ponzi that holds 0 assets and is just one giant liability.