If conservatives had reason to be confident that a Republican Senate majority (and eventually a GOP White House) would govern conservatively, perhaps there would be a better case for waiting until after the heat of an election season to lay out policy details.
The problem is that it’s always election season — meaning there’s always an available excuse. As soon as the midterms are over, the focus of the political world will turn immediately to the 2016 presidential election. There will be voices warning that a Republican Senate shouldn’t be too bold in passing legislation in 2015 or 2016 because it could undercut the presidential nominee. Conservatives will be told that retaking the White House is the only way to implement conservative reforms. By 2017, the excuse may be that Republicans don’t want to fall into the same political trap as Obama and “overreach” on policy, risking a backlash in the 2018 midterms. And so on.
To be sure, some Republicans understand that merely skating by isn’t good enough. Nebraska U.S. Senate candidate Ben Sasse, for instance, has actually proposed an alternative to Obamacare.