The Jim Bolger-trained three-year-old, third to Dubawi in the Irish 2000 Guineas on his last run, was made to battle all the way down the straight to get the better of Zarad.
Kevin Manning had Democratic Deficit well placed just behind the leaders coming off the final bend in the seven-furlong Group Three contest and threw down his challenge at the same time as Zarad.
The pair were locked in a terrific duel before the 8-13 favourite edged into the lead for a head victory, with Simple Exchange running on really well to take a close-up third.
It was the winner’s second victory of the season as he landed the Craven Stakes at Newmarket before returning there to finish sixth in the 2000 Guineas.
Bolger revealed that Democratic Deficit’s bridle had been changed to make him an easier ride.
“But he objected to it all the way and we were lucky to get away with it,” he said.
He would not rule out a trip to Royal Ascot at York next week, but added: “I’ll just sleep on it and we’ll wait and see.”
It was a great evening for Bolger, with Democratic Deficit’s victory the highlight of a near 955-1 four-timer.
Manning also won on the trainer’s Ambika (12-1) in the Irish Stallion Farms EBF Fillies Maiden and What’s Up Doc (11-2) in the EAP Tote Conference Handicap. Claimer David Moran then completed the quartet by winning the Derrinstown Stud Apprentice Handicap on Koukalova (6-1).
Chelsea Rose (4-1) put up a gutsy performance on her seasonal debut to win the Jockey Club Of Turkey Silver Stakes. Solskjaer and Sublimity went off at a terrific clip in the Listed 10-furlong contest and were soon well clear, but they paid the penalty as those in behind dominated the finish.
Pat Shanahan brought Chelsea Rose through to challenge off the final bend and soon led, but 11-4 favourite Merger arrived on the outside to throw down a determined bid. The filly, winner of the Group One Moyglare Stud Stakes last year and carrying a penalty for that, would not be denied, however, and battled all the way to the line for a head triumph.