Yes, Congress did not do well, and therefore the majority was reversed in 2006. However, given the rise of the Tea Party and their (sic!) win in 2010, the sitting GOP members should be aware that much can happen in the primaries.
No, I don’t think R/R will tell Congres to leagalize gay marriage, and I don’t think any except a slim minority of the republicans in the Congress would vote for such a law.
The Tea Party was a total flop in the primary. Then the Supreme Court decision approve Obama/Romneycare took the wind out of it’s sales. Now the Tea Party totally sold out to Romney. They are no resistance to him anymore. Basically, it’s, “any socialist but Obama,” now.