Dave was born in 2230. Supreme Commander and President for Life, Dave is the descendant of those who fled to the hills and managed to survive the war. His family has lived there for the last 200 years. His "citizens" are mostly descendants of his own ancestors or others with similar mindsets. Over the years, Dave's tiny plot of land has been also known as the "Kingdom of Larry", the "Republic of Stevie-Ray", "Billsylvania", the "New Republic of Stevie-Ray", and most recently, the "Kingdom of Tom" after Dave's father. Dave, now 47 years old, strongly believes that his land is a functioning nation and considers the compound his sovereign territory. He was briefly banished from this place during his father's presidency, and did some work with Allistair Tenpenny. Dave hates Tenpenny and people like him, and doesn't want to be reminded of the past.
Dave re-wrote his Republic's marital laws shortly after seizing control, in order to get himself a second wife, Jessica. The excuse given to his first wife was that "he needed to re-populate the land of Dave so they could grow and soon own all of the Capital Wasteland".
Election Day: Dave asks you to gather the republic's citizens for the upcoming election for a small reward. You can vote for Dave (after paying the 250 caps immigration fee), or encourage his first wife Rosie or his son Bob to run against him. You can also tamper with the ballot box to make it possible for someone other than Dave to win.
If Dave loses the election, he will leave the Republic forever and retreat to Old Olney, which he will declare the New Republic of Dave. Thereafter, he will be found sitting in the gore-strewn alleyway just a few feet from the fast-travel arrival location. Speaking to him repeatedly afterward will result in him turning hostile. Dave will more than likely be killed by deathclaws in Old Olney, as his chosen waiting location is within sight of at least two deathclaws' regular patrol routes.
Additionally, once Dave leaves the immediate area surrounding the Republic of Dave, he can be killed without the other inhabitants of the Republic becoming hostile. Despite this, some will still act as if Dave has been killed, but in a way that is not hostile. For example, Jessica says "Dave is dead. How can we have an election with no president?"
How the Lone Wanderer greets Dave in their first meeting plays a large role in how Dave will interact with the player. If greeted with the Wasteland Ambassador route, it will give him a false sense that the Republic is being recognized as sovereign, and he will interact fairly well. If you request asylum, you will receive a neutral interaction from him from there on out. If you tell Dave that his "Republic is forfeit", Dave and all the other inhabitants of the Republic will become hostile.
At night Dave can be heard talking in his sleep about killing all ghouls (although both Crowley and Quinn state during the quest You Gotta Shoot 'Em in the Head, that Dave is actually not a ghoul hater).