The US Senate has voted overwhelmingly to give states the power to enforce their sales tax laws on online purchases, but the legislation faces a tougher fight in the Republican-controlled House of Representatives. The Senate passed the bill by a vote of 69 to 27, getting support from Republicans and Democrats alike. But opposition from some conservatives who view it as a tax increase will make it a tougher sell in the House. US President Barack Obama has conveyed his support for the measure. Under current law, states can only require retailers to collect sales taxes if the store has a physical presence in the state. That means big retailers with stores all over the country like Wal-Mart, Best Buy and Target collect sales taxes when they sell goods over the Internet. But online retailers like eBay and Amazon don’t have to collect sales taxes, except in states where they have offices or distribution centers. As a result, many online sales are tax-free, giving Internet retailers an advantage over brick-and-mortar stores. The bill would empower states to require businesses to collect taxes for products they sell on the Internet, in catalogs and through radio and TV ads. Under the legislation, the sales taxes would be sent to the state where the shopper lives.