WASHINGTON (AP) — Donald Trump’s pick to lead the Treasury Department, Stephen Mnuchin, built his reputation and his fortune as a savvy Wall Street investor. But one of those investments has put him in the crosshairs of Democrats as he heads into his confirmation hearing Thursday: sub-prime mortgage lender IndyMac bank. Mnuchin, who served as Trump’s finance chairman during the campaign, has defended his role in the purchase of the failed bank, whose collapse in 2008 was the second biggest bank failure of the financial crisis.