I'm not sure of the meaning of the expression "We give up on singles and doubles" in the phrase "We give up on singles and doubles, hoping some slugger will come along and swing for the fences".
Is it something like in money games in casinos ?
From The Atlantic
Achieving results nationally means participating locally. The scale of the country’s challenges can seem so vast that only grand solutions offer any hope of meeting them. We give up on singles and doubles, hoping some slugger will come along and swing for the fences. This is wrong on two counts. First, the steep decline of democratic participation is itself one of our central challenges, reflecting a loss of conviction that government is actually in our hands. Only participation can solve the participation problem. Second, the impact of participation trickles up. Rosa Parks didn’t start out by taking on all of Jim Crow; she started out by taking a seat on a local bus. National efforts on the environment, health care, highways, the minimum wage, workplace safety—all got their start in one state or another. And Washington isn’t synonymous with America, anyway. Community life is sustained locally, not only through government but through a wealth of civic associations that depend on the participation of ordinary people. The president famously possesses a bully pulpit, but the impetus for change just as often comes from the pews.