By April 2016, Clinton had begun discussions with advisers and allies regarding her potential running mate, though Bernie Sanders continued to challenge her in the Democratic primaries. According to campaign sources, Clinton did not have a particular running mate in mind, and did not feel pressured to pick a running mate designed specifically to appeal to Sanders supporters. There was relatively little public discussion about Sanders's running mate selection process. As the 2016 Republican National Convention took place roughly one week before the July 25–28 Democratic National Convention, the Democratic presidential nominee was set to choose her running mate after the Republicans nominated their ticket of Donald Trump and Mike Pence. Clinton's running mate selection process was led by campaign chairman John Podesta and Cheryl Mills, while the vetting process was led by attorney James Hamilton. In discussing her potential vice presidential choice, Clinton stated that the most important attribute she was looking for is the ability and experience to immediately step into the role of president. In contrast to previous Democratic presidential nominees, Clinton allowed for a relatively open selection process, holding rallies with many potential running mates and placing little emphasis on keeping her short list confidential.