Hillary is doing a fine enough job getting herself into hot water. It does not really matter what Bill does. The general public has always found Bill to be charming anyways, so they will most assuredly forgive and forget. Hillary has never been well liked by anybody, including her own family.
Yes, Bill Clinton is hurting his wife's campaign. Bill Clinton seems to love drawing the attention to himself, whether that attention is negative or positive. Because of this attention-seeking behavior, he has made numerous political blunders over the years. Meeting with Loretta Lynch was very bad, just like it was very bad when he has screamed and threatened people both in this election and in 2008 who disagreed with him or his wife.
Bill Clinton is hurting Hillary's campaign for the presidency. Bill's private meeting with Attorney General Loretta Lynch last week stirred up a lot of controversy in the media. This controversy will likely hurt Hillary with Independent voters. Furthermore, Bill has made numerous remarks throughout this campaign that have caused Hillary trouble as well. In short, Bill Clinton does seem to be hurting Hillary's campaign.
Most notably, his "accidental" meeting with Attorney General Lois Lynch on an airport tarmac on a Saturday is obviously related to the FBI's decision not to recommend that Hillary be charged with criminal offenses related to her email scandal. There are still a lot of people in Washington who are loyal or how the Clinton's a debt, and this is an obvious example of him using his stature to intervene on her behalf. Even the most naive politico would know that they should avoid the appearance of any impropriety, but the Clintons are so accustomed to bending the rules to their purpose that they no longer make an effort. Hillary owes Bill a big thank you this week.