From the WSJ editorial on the French vote:
One lesson Americans shouldn’t draw, however, is that this is somehow a defeat for the common European currency, despite its 1% speculative fall against the dollar yesterday. The euro’s impact may well have contributed to the French defeat by exposing the failure of socialist economic policies. The repudiation earlier this month of Chancellor Gerhard Schröder’s Social Democrats in their heartland of North Rhine-Westphalia had similar economic causes. The low-tax challenge from other European nations is precisely what many supporters of the euro, including us, had hoped for. The euro has been a liberalizing force in Europe, while the constitution was designed to be centralizing force.