While Pennsylvania hasn’t voted Republican in a generation, the state has moved closer to the GOP over recent elections. | AP Photo Clinton launches Pennsylvania ad buy

Hillary Clinton is officially expanding her television ad campaign to Pennsylvania in advance of the national party convention in Philadelphia next week — yet another sign that the presumptive Democratic nominee is defending that state, which hasn’t awarded its electoral votes to a Republican presidential candidate since 1988.

A media-buying source said Monday that Clinton’s campaign was purchasing airtime in markets across the state. The flight of ads will cost the campaign at least $680,000 for the week beginning Tuesday, the source said. The national party convention begins next Monday.

Pennsylvania wasn’t part of Clinton’s initial ad buys. But the pro-Clinton super PAC Priorities USA Action expanded to Pennsylvania earlier this month, and Clinton’s campaign had made inquiries about running addressable TV ads on satellite platforms in the state.

A Clinton campaign official confirmed the ad placements on Monday.

While Pennsylvania hasn’t voted Republican in a generation, the state has moved closer to the GOP over recent elections — even as Democrats have moved traditionally Republican states like Virginia and Colorado into their column.

Clinton leads by 6.2 points in the current POLITICO Battleground States polling average. But that's driven by divergent polls: Clinton led by 9 points in a NBC News/Wall Street Journal/Marist poll out last week, but Trump was up 2 points in a Quinnipiac University poll.