One for the end of the road? Merry Clinton knocks back whisky on campaign plane

The Democratic presidential hopeful was flying back from Rapid City in South Dakota, one of the few states yet to hold its primary when she decided to let her hair down a little.

Her relaxed mood may give rise to speculation she is preparing to concede to her Democratic rival Barak Obama.

A wee dram: Mrs Clinton jokes with reporters on her campaign plane prior to takeoff from the airport in Rapid City

Relaxed: Hillary Clinton could be about to exit the race to become the Democratic Party's presidential nominee

Earlier in the campaign, Mrs Clinton regularly took time out to enjoy a drop of the hard stuff with voters but she avoided informal contact with reporters

Earlier, she took a couple hours out of her not-so-busy schedule for a little sightseeing, driving in her 7-car motorcade up to Mount Rushmore.

Her appearance startled the handful of tourists at the shrine to the presidency on a cold and overcast morning.

One woman approached her and said: “Thank you for running.”

Mrs Clinton replied: “I need your help.” Another, who happened to have a copy of Mrs. Clinton’s “Living History,” handed it her to be inscribed.

As Mrs. Clinton received a briefing on the sculpture from a park ranger, her press entourage pressed in with boom mikes and clicking shutters, but she was in no mood for levity or cheap metaphors.

She brushed off the predictable press questions: “Can you see yourself up there?” and “How about your husband?”

Mrs Cluinton replied: “This isn’t a press event. It’s a tourist occasion. Why don’t you learn something?”

She has two more public events scheduled on Wednesday, at the Pine Ridge Sioux reservation in the afternoon and in Sioux Falls in the evening.