If you do not think the establishment republicans are "leftist lite" your delusional.
Are referring to someone who we all are familiar with, like a Naval Aviation who was released from a North Vietnamese POW camp in 1973, with carrier ending injuries but who none the less was able to keep his commission and serve another 7 years, retiring as a Navy Captian. This was mainly because his Daddy and his Granddaddy both were 4 star Admirals? If that is an example of a "leftist light" then I must disagree with you. The above man is an example of a stodgy elite Apparatchik intrested only in feathering his own nest, not in serving his country.
If on the other hand you are referring to those folks who call themselves "Tea Party Patriots" or some other such self congratulatory term, but who when push comes to shove would rather sit on their hands on election day than work or vote for a candidate who these so called patriots find insufficiently conservative, resulting in the election of hard core leftists. If that is the kind of GOP leftist light you are speaking about then I agree 110% with your description of these people as "light lefties."
If however you mean folks like the Tea Party politicos who recently encouraged Uber Liberal singer Ashley Judd to run as a Democrat against Mitch McConnell for his US Senate seat because these self anointed "patriots" have their Depends in a wad over a few of GOP Senator McConnell's votes? If these are the people you are calling leftist lights, I suggest that you call these people what they really are, Obama sleeper cells. These Tea Party politicos are stooges and enablers of the far left wing of the Democrat Party but nothing better.
Political parties are called parties mainly because they hope to attract as large a following as possible and the price of admission to any political party is your vote and support. If you withhold either your vote or support you don't belong to either party and therefore you lose your right to criticise both parties. Political parties are NOT "I'm gonna hold my breath until I get my way or else turn 'blue' in the face societies" as some of the new to the election process tea-bibbers seems to think. For better or for worse, the Tea Party reminds me of the 19Th Century Mugwump Party who despite their Republican leanings could not bring themselves to vote for Blair, the 1884 GOP nominee resulting in the first Democrat to be elected President in 28 years, Grover Cleveland.
One thing that validates my point is the beyond dismal showing most Tea Party candidates made in red state Senate races starting in 2010. If it were not for the Tea Party there would be a center right majority of GOP Senators today. That means that win lose or draw in the presidential election of 2012 that Barrack Obama would now be sucking air just to stay afloat politically. At the end of the day it reminds me of the old East Coast liberal mantra, "I would rather be Red than dead" only in this case it means, "I would rather Obama Care kills my dumb arse than vote for a mainstream GOP candidate."
A clear indicator of the tiny amount of power that the Tea Party wields is the example that was made of Tea Party darling Jim DeMint of South Carolina. The reason that a young DeMint unexpectedly resigned from the US Senate in the aftermath of the 2012 election was DeMint's efforts to recruit and fund Tea Party losers like O'Donnell, Angle, Murdock, and others who all proved disastrous as candidates by pulling crushing defeats out of the jaws of sure victory. DeMint did more to elect Democrat Senators than Obama and the Democrat Party put together. Obama and the DNC are gonna miss DeMint. I hope that Senators Rubio and Cruz don't try to fill DeMint's shoes. Paraphrasing the title of one of Billary Clinton's books, "It'll take a manure spreader to fill DeMint's shoes."