Rep. Spencer Bachus Monday (R-Ala.) chastised Democrats for feet-dragging on reforming the government-sponsored enterprises. But housing strategists at the Royal Bank of Scotland expect Republicans will move no faster. Changes to Fannie Mae and Freddie Mac will likely take up to 15 years to fully implement, according to RBS analysts. Broken down broadly, all of the suggested reforms can go into two broad categories for the secondary mortgage market. The RBS analysts said the first type of structure for housing creates a single mortgage-backed securitization method that conforms to a standardized underwriting process and is explicitly backstopped by the government after all other support levels are exhausted. The second has no role for the government in housing finance and transitions the market to one that's fully private dominated by high credit with securitization provided by banks. Loss provision in this case varies wildly, from private insurance to catastrophic funds. Any any rate, RBS analysts add, a rush to change may put the secondary mortgage market at risk. An end politicians are eager to avoid, regardless of party affiliation. In the interim, "upcoming Congressional hearings on GSE reform are likely to result in political posturing and headline risk," said RBS GSE analysts Margaret Kerins and Ryan Graf. "The tail risk fear is a Republican government abandoning support for GSE debt or recouping losses from senior debt holders, which would also create credibility and funding issues for Treasury." "This would be inconsistent with the government's commitment to stability," the analysts said. "Even the Republicans propose a gradual wind down of the GSEs over about 15 years." Write to Jacob Gaffney. Follow him on Twitter @JacobGaffney.