Lecompton Democrat. Since the beginning of the 1850s, issues regarding slavery had effectively split the California Democratic Party. By the 1853 general election campaign, large majorities of pro-slavery Democrats from Southern California, calling themselves the Chivalry (later branded as Lecompton Democrats), threatened to divide the state in half, should the state not accept slavery. John Bigler, along with former State Senator and Lieutenant Governor David C. Broderick from the previous McDougall Administration, formed the Free Soil Democratic faction, modeled after the federal Free Soil Party that argued against the spread of slavery.
The Democrats effectively split into two camps, with both the Chivalry and Free Soilers nominating their own candidates for the 1853 election. By 1857, the party had split into the Lecompton and Anti-Lecompton factions. Lecompton members supported the Kansas Lecompton Constitution, a document explicitly allowing slavery into the territory, while Anti-Lecompton faction members were in opposition to slavery's expansion. The violence between supporting and opposition forces led to the period known as Bleeding Kansas. Splits in the Democratic Party, as well as the power vacuum created by the collapse of the Whig Party, helped facilitate the rise of the American Party both in state and federal politics. In particular, state voters voted Know-Nothings into the California State Legislature, and elected J. Neely Johnson as Governor in the 1855 general elections.