“Republicans lost the White House in 2008 and again in 2012, because Sen. John McCain and Massachusetts Gov. Mitt Romney failed to ignite conservative passions.”
Actually Republicans have lost 6 of the last 7 presidential elections in which they ran a moderate big government establishment candidate: 1992, 1996, 2000 (remember George W Bush lost the popular vote in 2000), 2008, 2012. Only in 2004, when George W. Bush was reelected, did the GOP brand win the popular vote, and that election was very close (Bush won 50.7% to 49.3%).
The last 7 presidential elections indicate at the national level a leftist redistributionist big government candidate will win running agains a corporatist big government candidate. The only reason I can think of the GOP would run such a candidate is a conscious desire to lose.
Apart from a conscious desire to lose is the absolute determination to prevent a conservative from getting nominated.