I have read through the three budgets coming from the Democrats in Congress: the CPC's Back2Work Budget, the Senate Democrats' Budget, and the House Democrats' Budget.  The CPC Budget is the only one that promises no benefit cuts from Social Security.
"No benefit cuts to Medicare, Medicaid, or Social Security" (p. 1, Exec. Summary).
The Senate Democrats and the House Democrats, on the other hand, both plant the seeds of what will become a false dilemma: chained CPI or the bogeyman of privatization.
The House Democrats' Budget reads:
"Protect Social Security from Privatization--The Social Security Trust Fund is fully funded until the year 2033.  After that, it will pay 75 cents on the dollar of currently scheduled benefits.  The President and Congress should work on a bipartisan basis to close that gap.  However, the Democratic budget affirmatively rules out privatization--we should not gamble Americans' retirement security on Wall Street" (p. 6, emphasis added).
We see a few things at work in this passage.  First, we have the framing of Social Security as a problem that needs immediate solving, even though it's fully funded for almost 30 years.  Then, we have the emphasis on the need for "bipartisan" solutions.  I think we all know that Republicans are not going to support raising the payroll tax cap in the various ways that Senators Sanders, Harkin, and Begich have proposed (with companion bills in the House by Rep. DeFazio and Rep. Deutch).  Last, we have the looming specter of privatization.  The Ryan budget, however, does not call for privatization even though Ryan has certainly endorsed that in the past.  The Democrats are creating a fictitious enemy here so that they can say that they had to accept chained CPI because the only other possible solution was to privatize Social Security as the mean Republicans wanted to do.  A false dilemma, par excellence.

A similar evasion exists in the Senate Democrats' budget:
"Social Security plays a critical role in providing a foundation of financial security for nearly 60 million seniors, survivors, family members, and people with disabilities. The Republican approach, however, would weaken the traditional three‐legged stool of Social Security, pensions, and savings, leaving hardworking low‐income Americans to fend for themselves as they try to save for retirement. Unlike past Republican proposals that would seek to privatize and weaken Social Security, the Senate Budget ensures the guarantee remains" (pp. 97-8).
The Senate language is not nearly as bad as the House language; however, we again see the stirrings of a false dilemma in the specter of privatization. Even the word "weaken" has a vagueness to it as Pelosi has said (in an embrace of Democratic newspeak) that chained CPI would "strengthen" Social Security.

So, in conclusion, stay alert for the "Grand Betrayal" as its outlines begin to take shape.