Economists at Goldman Sachs Group Inc. have lowered their forecast for growth in the U.S. economy this year for a second time, citing the COVID-19 Delta variant and dwindling fiscal support and pointing to a “harder path” ahead for the American consumer than previously anticipated. In a report to clients on Monday, economist Ronnie Walker wrote that overall expansion in 2021 is now seen at 5.7 percent in comparison with an expected rate of 6 percent published at the end of August. While consumption in the United States has jumped by 16 percent since the worst of the pandemic and also returned to its pre-virus state in the second quarter, Walker painted a gloomy path forward, with plenty of hurdles to overcome. Explaining the reasoning behind the lowered forecast, Walker wrote that American consumers are likely to spend less money amid the surge in the Delta variant of COVID-19, while fading fiscal stimulus …