Washington (AFP) – Donald Trump’s victory in the US presidential election four years ago brought into question as never before the reliability of opinion polls. Can they be believed this time around?What do the polls say?With 16 days to go before the November 3 election, Democrat Joe Biden is ahead of the Republican president by 9.0 percentage points nationally, according to polling averages from the RealClearPolitics website.But in the United States, candidates win the White House not through the popular vote, but with the Electoral College. In 2016, Trump lost the popular vote to Hillary Cli…