MADRID (MarketWatch) -- U.S. stock-market futures were piling on losses early Wednesday as investors grew increasingly worried about political loggerheads over the budget and the potential impact on debt-ceiling negotiations. A European Central Bank meeting and an Italian vote of confidence on the government there are also on the cards for Wednesday. Futures for the Dow industrials DJZ3 -0.66% fell nearly 100 points, or 0.7%, to 15,021, while those for the Standard & Poor's 500 index SPZ3 -0.76% fell 12.70 points, or 0.8%, to 1,676.70. Futures for the Nasdaq 100 index NDZ3 -0.66% dropped...continue