Was wasting time on youtube when I ran across this
Harold Ford Jr v Kos in late 2007. The GOP's power struggles with itself has reminded me (a bit) of the DLC v progressive movement the democrats faced in the mid 2000s, especially after Kerry's loss. The 2008 election certainly looked good for democrats in late 2007, but there was still a pretty open leadership battle between the more centrist Clinton folks and the Howard Deans, John Edwards, and eventually Barack Obamas - enough that you could rightfully wonder whether dems could get their shit together or face a repeat of 2004.
There were plenty of people waiting in the wings to revive the DLC "we were too liberal!" memes if Obama had lost in 2008 (remember Evan Bayh?), or 2012 (Ed Rendell, Andrew Cuomo) for that matter. There still are some center-left think tanks/groups like Third Way, but for the most part the Clintonista DLC structure has been purged. The Joe Liebermans, Harold Ford Jrs, etc have largely been rendered irrelevant. Likewise the Blue Dog coalition has been almost completely annihilated in congress.
While I wouldn't compare the current activist right (tea party, Red State, etc) to the activist left (Daily Kos, MoveOn, etc) of the 2000s, they're certainly in a similar position compared to liberals back then. Being belittled, pushed out, establishment candidates winning presidential nominations over the movement candidates, etc. The biggest difference seems to be that conservatives are historically unable to buck the establishment candidate, whereas democrats constantly do. Traditionally the modern democrat party is composed of enough large groups (labor/unions, liberals, minorities, youth vote, etc) that an insurgent candidate can form successful coalitions, whereas I'm not sure this really happens with republicans anymore. Their coalitions seem more based around pure ideological wings (hawks, religious right, fiscal conservatives, etc) that tend to rally to the establishment candidate. Also in terms of pure numbers, the religious right seems like the only large group able to shift a primary race, whereas there are multiple groups that can do that for democrats.
TLDR: A shitty president, demographics, and coalition building have given democrats a lot of long term electoral advantages, whereas republicans seem to be stuck with a 20th century model; the smoky dark rooms of the 60s conventions may be extinct, but ultimately the establishment still picks the nominee, and the activist base can't do much to stop it because republicans continue to fall in line rather than fall in love.