Mitch McConnell, Alison Grimes on the attack at Kentucky picnic

Senate Minority Leader Mitch McConnell's tough bid for re-election became a heated back-and-forth of one-liners and personal attacks as he appeared alongside Democratic rival Alison Lundergan Grimes at an annual Kentucky picnic.

The stakes are high. The race is one of the toughest in McConnell's 30 years in the Senate, and victory is far from guaranteed. And a win could amount to a promotion to Senate majority leader if Republicans win enough races against Democratic incumbents.

The annual Fancy Farm picnic in western Kentucky Saturday put the candidates side-by-side as they sought to rally their respective bases. They both opted for a combative style.

McConnell painted Grimes as far too much like President Obama, particularly when it comes to her qualifications.

"He didn't have any qualifications at all," McConnell said, likening her limited political career to Obama's lightening-quick rise from senator to president in less than four years, according to the New York Times. "Sound familiar?"

He had some helpful context from recent fumbles by Grimes, who appeared not to know what Israel's Iron Dome missile defense system was used for earlier this week when she suggested it protected Israel from tunnels built by Hamas.

Grimes, in turn, played up her relative youth relative to the 72-year-old McConnell.

"Thirty-five is my age," said Grimes, according to the Washington Post. "That's also Senator McConnell's approval rating."

While steering clear of difficult political issues like the Affordable Care Act, she has embraced other parts of the Democratic agenda such as criticizing Republicans for blocking equal pay legislation and an increase in the minimum wage.

McConnell has turned to his fellow Kentuckian, Republican Sen. Rand Paul, for help on the campaign trail. Both he and McConnell suggested a Grimes victory would be harmful to the deeply rooted Kentucky coal industry.

"When she takes the first vote for Harry Reid, she kills any chance of resurrecting the Kentucky coal industry," Paul said.