After the nonpartisan California Legislative Analyst’s Office recently put the proposed pension ballot measure attacking retirement security on the ropes with its finding that it would create “significant uncertainty,” the state’s top two pension systems may have delivered knockout punches this week.

In letters to Assemblymember Rob Bonta (D-Oakland), chairman of the Assembly Committee on Public Employees, Retirement, and Social Security, the CEOs of both CalPERS and CalSTRS noted the measure was fraught with problems.

The list of pitfalls they identified is long, and includes two points that have doomed previous measures: effectively ending death and disability benefits for firefighters and police officers, and eliminating retirement security for current (as well as future) employees.

In her letter, CalPERS CEO Ann Stausboll said the measure would “arguable curtail the California rule for existing employees” as well as new public workers. That’s a key point: Former San Jose Mayor Chuck Reed and former City Council member Carl DeMaio had said that was not the case. Stausboll says they’re wrong.

(The “California Rule” provides that employees are roughly entitled to the same set of benefits for future work performed as were in place the day they started working.)

More devastatingly, Stausboll said it would “almost certainly make providing death or disability benefits extremely impracticable.” Similar provisions in the pension proposal put forward by then-Gov. Arnold Schwarzengger caused him to pull that measure from the 2005 ballot.

Earlier in the week, CalSTRS CEO Jack Ehnes noted that “this measure would …impose additional risks on the plan’s ability to achieve full funding…An additional consequence is that CalSTRS’ cash flow would become increasingly negative, impacting CalSTRS’ investment decisions,” forcing the fund to change its investment strategy and cause taxpayer contributions to increase to cover lower expected returns.

CalPERS echoed that concern, noting that it would likely force the fund to lose its tax-exempt status from the IRS.

CalSTRS also noted that the “impact of the measure would fall most heavily on women. Nearly 70 percent of CalSTRS’ members are women, many of whom interrupt their careers to raise families. Those who wish to do so likely would be deprived of their portable membership rights, since they will be treated as ‘new employees’ who will not be allowed to continue to participate in CalSTRS unless voters in the jurisdiction of their school district affirmatively act to permit their participation.”

Just weeks ago, Reed had called the measure “bulletproof.” But it appears that this year’s pension measure shares many of the same problems of previous versions, making it increasingly vulnerable to attacks from a well-funded opposition campaign.