The Counterfeit Candidate by Brian Klein (The Reich Trilogy #1)

Berlin, 30 April, 1945
As the Russian Army closes in on the war-torn City, Adolf Hitler and Eva Braun take their own lives. Their bodies are burned and buried in the Reich Chancellery garden, above the Führer's bunker.
Buenos Aires, 9 January, 2012
Three audacious thieves carry out the biggest safe depository heist in Argentine history, escaping with more than one hundred million dollars' worth of valuables. Within hours, an encrypted phone call to America triggers a blood-soaked manhunt as the thieves are tracked down, systematically tortured, then murdered.
San Francisco, 18 January, 2012
Senator John Franklin, hailed as the 'Great Unifier', secures the Republican Presidential nomination and seems destined for the Oval Office. Despite the sixty-seven year interval and a span of thirteen thousand miles, these events are indelibly linked.
Chief Inspector Nicolas Vargas of the Buenos Aires Police Department and Lieutenant Troy Hembury of the LAPD are sucked into a dark political conspiracy concealing an incredible historical truth stretching from the infamous Berlin bunker to Buenos Aires and to Washington, which threatens the very heart and soul of American democracy.