Have moderate Republicans been losing the presidency because conservative voters stayed home in protest?

Ramesh Ponnuru says no:

Conservatives sometimes argue that Republicans lost the last two presidential elections because they nominated moderates who did not inspire conservatives to vote. On NRO today, Bernard Goldberg places blame on those conservatives who stayed home. He writes that “millions of the ideologically pure — who normally would vote Republican — did in fact sit home, if not handing the elections to Barack Obama, at least making it a lot easier for him to win.”

The premise of both arguments–Republicans shouldn’t have nominated moderates because they can’t turn out conservatives, and conservatives shouldn’t have sat out the elections–does not appear to be correct, based on the exit polls. There was no drop-off in conservative turnout in either 2008 or 2012. Conservatives were 34 percent of the electorate in 2004, 34 percent in 2008, and 35 percent in 2012. They voted Republican at a normal rate in 2012 too: Romney got 82 percent of them, a bit lower than George W. Bush’s 84 percent in 2004 but higher than his 81 percent in 2000. (McCain did a bit worse in 2008, with 78 percent.) Goldberg’s argument could end up being true about 2016, but it has not been true in the last two elections.