If conservatives believe in low taxes in order to keep government small, so be it, but when they insist that low taxes are necessary for a healthy economy, they are talking rot, parroting a mantra that has been utterly disproved.
A number of other countries can tell a similar story. The proof is irrefutable. Indeed, we can go further. Not only do high taxes not preclude a robust economy, they may be necessary to achieve a nation's best economic performance. After all, in the modern world an optimal economy requires excellent social infrastructure—a healthy, well-educated population in which all members can fulfill their potential. And it requires excellent physical infrastructure—good roads, docks, water and sewer facilities, etc. And excellence costs money. Low taxes can't afford it.
How taxes are applied is another matter. Different taxes create different incentives and disincentives, so which taxes a government emphasizes can be important to economic health, and this certainly deserves debate. But that high overall taxation is in itself a disincentive to an economy is an argument deserving of a quick trip to the ideological dumpster.