JULIE STEENHUYSEN  DR. Anthony Fauci, the nation's top infectious disease expert, said political divisiveness contributed significantly to the "stunning" U.S. COVID-19 death toll, which on Monday surpassed 500,000 lives lost. The country had recorded more than 28 million COVID-19 cases and 500,054 fatalities as of Monday afternoon, according to a Reuters tally of public health data. In an interview with Reuters, Fauci on Monday said the pandemic arrived in the United States as the country was riven by political divisions in which wearing a mask became a political statement rather than a public health measure. "Even under the best of…