If nothing else, the European crisis has brought fears of another economic meltdown back to a head. If the gloom-and-doomers are right, Dollar Tree offers some significant downside protection right now. That's because as consumers trade down and limit expenses, Dollar Tree is ready to serve them with bargains.The firm is working on the higher-end of the consumption chain, too. It's been expanding the footprint of its multi-price point Deal$ brand, a move that should open the door to bigger-ticket merchandise at higher margins. >>2 Stocks to Buy Because the Wealthy Rule America When Dollar Tree's demographics changed in 2008, so did its store operations. The firm started accepting major credit cards and integrating EBT transactions into its new point-of-sale system, courting two new customer bases. And (surprisingly) Dollar Tree's net margins have historically stomped traditional retailers, sending more cash to the firm's bottom line, and giving DLTR the ability to pay off its $250 million debt balance last quarter. While shares of Dollar Tree aren't exactly a deep value themselves right now (its P/E currently sits at 23), its defensive posturing and U.S.-focused income statement makes up for it. Dollar Tree, one of the 10 Best-Performing S&P 500 Stocks in the Second Quarter, also shows up on a recent list of 6 Stocks Benefiting From Lower Gas Prices.