evidence: WASHINGTON — The financial sector, blamed by progressives for spawning the 2008 economic collapse, is lining up behind Pete Buttigieg’s presidential campaign. [...] While Buttigieg is hardly alone in turning to the finance industry for support, the data could leave him exposed to further attacks from his progressive rivals, especially Sen. Elizabeth Warren. The Massachusetts Democrat's criticism of big banks during the economic collapse helped propel her political career and she repeatedly hit Buttigieg during Thursday's presidential debate for his ties to large donors. [...] One top Wall Street law firm could pose particular challenges for Buttigieg with progressives. He's the top recipient of cash this cycle from Sullivan & Cromwell, which has worked on some of the biggest corporate mergers in recent history, including Amazon's acquisition of Whole Foods, AT&T’s purchase of Time Warner and Bayer’s merger with Monsanto. The firm also represented some of the largest financial institutions that received federal bailout money.