evidence: Joe Biden announced plans to triple tariffs on Chinese steel and aluminum and promised to block the acquisition of US Steel by a Japanese company during a speech to steelworkers on Wednesday in the battleground state of Pennsylvania, where union support could prove crucial in the November general election. [...] Trump’s proposals would "badly hurt" American consumers and cost the average American family an average of $1,500 a year, Biden warned. In response, the Trump campaign said Biden had spent his entire career "betraying" working Americans by supporting Chinese membership in the World Trade Organization in 2011. The former president is spending much of the week in a Manhattan courtroom in his criminal trial.