DETROIT (AP) – The second set of Democratic presidential debates will be a last chance for some 2020 candidates to be considered serious contenders. The 20 hopefuls will face off Tuesday and Wednesday nights in Detroit. They will have the opportunity to respond to President Donald Trump’s recent string of racist and incendiary tweets and comments, but they’ll also be under pressure to provide specifics on how they can improve the lives of Americans. The stakes are high: To qualify for the third set of debates in September, candidates must raise money from more donors and hit higher polling thresholds – a bar more than half of the contenders are at risk of missing. Those tougher rules set by the Democratic National Committee are expected to winnow the race.