Kevin Starr Embattled Dreams California in War and Peace 1940-1950, Oxford University Press: Oxford, UK, 2002, 386 pp., 1938, 1935
[p. 257] "[Earl] Warren could do this, first of all, because of cross-filling, a direct legacy of the Progressive Era that had formed him as a young man and with which he maintained his deepest political identification. The Progressive years 1911 to 1923 witnessed the enactment of a series of political reforms in California that warred against the traditional political organizations of most Eastern states. In a effort to establish direct democracy, Progressive legislators in California approved the direct primary, cross-filing, the referendum, the initiative, and the recall. The referendum allowed the voters to bypass the legislature and make law directly. With a mere 250,000 signatures, an initiative could qualify for the ballot and be voted into law in a general election . . .
"In 1909, during the first administration of Progressive grovernor Hiram Johnson, California enacted the direct primary system. Political candidates could now go directly to the people without the approval of their party. In 1913 California established cross-filing . . . now candidates could enter both primaries . . . [p] Cross-filing lasted until 1959, when Democrats, swept in by the lan. 257dslide of 1958, abolished it.
[p. 258] "Not only did the Progressive era promote bipartisanship on the state level, it outlawed partisan politics in local elections . . .
[p. 262] " . . .