Last month, President Obama shot a friendly game of pool with Colorado Gov. John Hickenlooper (D). Today, that moment's popping up in a slightly less-friendly showcase: a Republican attack ad.

The Republican Governors Association is hitting the airwaves with its first TV commercial against Hickenlooper. The 30-second ad begins with footage of Hickenlooper and Obama trading shots at a brewery co-founded by the governor.

"John Hickenlooper is a fun guy to shoot pool with. But when it comes to making the tough decisions, Hickenlooper won't step up to the table," says the narrator.

The substance of the ad is more about Hickenlooper's record than his relationship with Obama. It hits him for signing gun control measures and granting a "temporary reprieve" to a convicted killer who was sentenced to death, among other things.

But the ad's imagery -- Obama and Hickenlooper hanging out informally -- and its implication that the governor is not a serious politician, could resonate with voters who don't like the president.

These days, there are a lot of them in Colorado. An NBC News/Marist poll of the state released last month showed just 40 percent of voters approved of the job Obama is doing as president. Fifty percent disapproved.

Obama won Colorado twice. But his popularity has dropped in his second term, as it has in most of the country.

Polls show a close race between Hickenlooper and former congressman Bob Beauprez, the Republican nominee. In response to the RGA ad, Hickenlooper released a video touting the state's economic progress and response to flooding.

"Four years ago we promised to run a positive campaign, and we did. We took the same approach across Colorado," he says.

The RGA spot is just one ad. On its own, it's not likely to shift the race in a major way.

But it provides as sampling of how eager Republicans are to tie Democratic candidates to the unpopular president. By giving them fresh material to work with, Democrats make their job easier.