Article II, Section 14(b) of the California Constitution mandates that the number of signatures to recall a member of the Legislatue "must equal in number 20 percent of the last vote for the office."

My associate in Sacramento crunched the numbers on the proposed/rumored recalls that may result from the tax hikes approved last week, and here are how many valid signatures required to qualify a recall against each of the six legislators who voted for the tax hikes:

Asm. Mike Villines: 33,466
Asm. Anthony Adams: 35,825
Asm. Roger Niello: 37,584
Sen. Roy Ashburn: 42,376
Sen. Dave Cogdill: 50,097
Sen. Abel Maldonado: 70,770

He also noted that it would require 29,834 valid signatures to qualify a recall against Asm. Jeff Miller.

The exact calculations are:
20% of 149,166 is 29,834 (AD-71: Miller)
20% of 167,330 is 33,466 (AD-29: Villines)
20% of 179,121 is 35,825 (AD-59: Adams)
20% of 187,916 is 37,584 (AD-5: Niello)
20% of 211,877 is 42,376 (SD-18: Ashburn)
20% of 250,483 is 50,097 (SD-14: Cogdill)
20% of 353,846 is 70,770 (SD-15: Maldonado)

These numbers are utilizing the 2008 election results for each district, except SD-18 (Ashburn) and SD-14 (Cogdill), which are calculated utilizing the 2006 election results since neither of those seats was up in 2008.

The results are calculated by adding the votes won by all of the candidates in each of those races (i.e. the legislator and all of his general election opponents combined).