They were led/driven by Tea Party ideas and their agenda the past two years
Actually, that is not true IMO. The Tea Party is the reason they control the House.
The GOP is in a weird position in that their base more closely aligns with TP ideals that the ideals of moderates or indies.
The main issue for the GOP is two-fold: (1) The Democrats have positioned themselves as the party of stuff and anti-personal accountability; and (2) demographics.
The GOP has no leadership that can effectively combat those two trump cards that the democrats now firmly hold.
If the GOP dropped all social issues from their platform they: (1) immediately lose a large portion of their base, and (2) even if they didn't lose their base, still don't gain any ground because they cannot out democrat the democrats.
Sadly, the only way for the GOP to regain footing is going to be a complete collapse of the economy such that the government checks dry up while the democrat are in control.