A contentious Nevada Democratic convention  this past weekend has led to a barrage of threats against the chairwoman of the state party.  And it's led the state party's lawyer to send a rather remarkable letter to the Democratic National Committee, warning of the risk of violent outbursts at the national convention in Philadelphia.    "Having seen up close the lack of conscience or concern for the ramifications of their actions—indeed, the glee with which they engaged in such destructive behavior—we expect similar tactics at the National Convention in July," wrote Nevada party counsel Bradley Schrager in a letter dated Monday. "We therefore formally complain to the DNC regarding these unfortunate events, and warn the body that the goal of many of these individuals, sanctioned or encouraged by the Sanders Campaign, is not party-building but something more sinister and unproductive." [Related: Democrats Get Physical] A Sanders spokesman told the Associated Press that the campaign had no connection to the violence at the weekend convention or the threats to the party chair.   Roberta Lange, a longtime Democratic operative and confidante of Senate Minority Leader Harry Reid, has faced a barrage of attacks not only in social media but also on voicemail and in text messages, some of which have been reviewed by Roll Call. "Hey bitch."  "Loved how you broke the system."  "We know where you live."  Want insight more often?
 Get Roll Call in your inbox "Where you work."  "Where you eat."  "Where your kids go to school/ grandkids."  We have everything on you."  "You made a bad choice. Prepare for hell."  "Calls won't stop."  One text message featured a person telling Lange that he was interested in buying a house near her home in Clark County, featuring her home address. The state party's headquarters was closed Monday for security reasons.  [Related: Crashing the Political Parties] The convention devolved into chaos after Hillary Clinton, the former Secretary of State and Democratic front-runner was awarded more delegates to the national convention than Sen. Bernard Sanders, I-Vt.  Clinton prevailed in the state's Democratic caucuses, but supporters of Sanders were well organized for local conventions.  Nevada political columnist Jon Ralston published extensive transcripts  of voice mails left for Lange earlier Monday evening.  Democratic operatives long associated with Reid in both political and official capacities were active on social media Monday night criticizing the Sanders campaign and calling for a rebuke of the behavior.   The Associated Press report on the situation Monday evening quoted Sanders' long time spokesman Michael Briggs as saying  "We do not condone violence or encourage violence or even threats of violence," while also adding that the Sanders' operation  "had no role in encouraging the activity that the party is complaining about. We have a First Amendment and respect the rights of the people to make their voices heard."