Butte, Montana. That’s where Barack Obama spent the 4th of July and where he spent his daughter Malia’s birthday:

BUTTE, MONT. — He hasn’t had a vacation for months. He sees his family little more than once a week. And now as the presumed Democratic nominee for president, he can’t go anywhere without being trailed by a full crew of journalists. Reaching his limit, Barack Obama wriggled free of the campaign’s fetters on July 4. Caught in Montana on his daughter Malia’s 10th birthday, he improvised a party. At the Holiday Inn Express in Butte, a city known for its copper mines and bordellos of old, Obama and family ordered a cake. They loaded an iPod with Malia’s favorite songs and danced and sang. Obama later came close to tears, recalling that Malia told him “it was the best birthday she’d ever had.”

But why was he in Butte anyway? Going back a few day in NY Times coverage of the campaign explains it:

While Mr. Obama believes he can take a run at a Democratic victory in Montana, there was far more on his itinerary here than simply meeting voters. He also spent time on a makeshift movie set – a political filming – to be shown at the Democratic convention in Denver.
Davis Guggenheim, the Academy Award-winning director of “An Inconvenient Truth,” was on hand in Butte with a large crew to film Mr. Obama. The piece is intended to tell the story of Mr. Obama’s life, as well as how Democrats believe they can win in the West.
The filming, which was not announced by the campaign, took place throughout the day on Friday at the Freedom Fest Independence Day celebration, followed by a picnic for about 1,000 people outside the World Mining Museum.
Additional filming with Mr. Obama took place at the Clark Chateau Museum, a mansion from the glory days of Butte, once known as the “Richest Hill on Earth” because of a lucrative mining industry.
Mr. Guggenheim, who was here with his own young son, is the son of Charles Guggenheim, a four-time Academy Award winner who chronicled President John F. Kennedy.

It was by choice that Senator Obama was in Butte on his daughter’s birthday and it was a purely political trip to provide a spectacular backdrop for his convention campaign video, as well as a backdrop for the debut of the Obama-kids on Access Hollywood. Yes, campaigns are hard on the families, but let’s call it what it is when a candidate decides to put politics first and then complains about the fallout on how it’s a burden on his personal life.