Since the 1923 gubernatorial contest, he had distanced himself from Haly and promised the conservatives that he would not push a ban on parimutuel betting if elected. Consequently, he had no opposition in the primary. Congressman (and later Chief Justice) Fred M. Vinson managed his general election campaign. Coolidge supported Ernst, and Commerce Secretary Herbert Hoover campaigned in the state on his behalf. Ernst had opposed a bonus for veterans of World War I, an unpopular position in Kentucky, and at 68 years old, his age worked against him. Barkley contrasted his impoverished upbringing with Ernst's affluent lifestyle as a corporate lawyer, and also attacked him for supporting Michigan Senator Truman Handy Newberry, who resigned due to allegations of election fraud. Republican voters were angered that Ernst did not support Republican Kentucky Congressman John W. Langley when Langley was charged with illegally aiding a large bootlegging operation in Louisville. Ernst tried to resurrect the issues of Barkley's support for the coal tax and opposition to parimutuel betting, but in the general election, Barkley won by a vote of 287,997 to 266,657. In the Senate, Barkley was assigned to the Committee on the Library, and the committees on Finance and Banking and Currency; later, he was added to the Commerce Committee. In early 1928, Vice President Charles G. Dawes assigned him to a special committee to investigate the campaign expenditures of the leading candidates in the upcoming presidential election. Democrats considered nominating him for vice president that year, calculating that his party loyalty and appeal to rural, agricultural and prohibitionist constituents, could balance a ticket headed by likely presidential nominee Al Smith, an urban anti-prohibitionist. When the Kentucky delegation arrived at the 1928 Democratic National Convention, they approached Smith supporters with a view to pairing Barkley to their candidate. They were received cordially, but Smith's advisors thought placing candidates with such differing views on the ticket would seem contrived to the electorate. They did not tell Barkley of their decision until after he seconded Smith's nomination for president. Smith then announced Arkansas Senator Joseph T. Robinson as his preferred running mate. The Kentuckians nominated Barkley in spite of Smith's preference, but the overwhelming majority of delegates voted for Robinson, and Barkley announced that Kentucky was changing its support in order to make the nomination unanimous. Barkley and his wife Dorothy took a vacation after the convention, returning to Kentucky in August 1928 to find that, in his absence, Barkley had been chosen state chairman of Smith's campaign.