Vermont Sen. Bernie Sanders holds substantial leads in the two largest states to vote on Super Tuesday, according to new CNN polls conducted by SSRS in California and Texas.

In Texas, Sanders holds 29% support among likely primary voters, former Vice President Joe Biden has 20%, former New York Mayor Michael Bloomberg stands at 18% and Massachusetts Sen. Elizabeth Warren is at 15%. No other candidate reaches double-digits. Sanders (+14) and Bloomberg (+13) have posted the largest gains since a December CNN poll, while Biden has slipped 15 points. Warren has held roughly even.

The California results suggest the same four contenders hold the most support, though Sanders stands well ahead of the three contending for second place. Sanders holds 35% support, Warren is at 14%, Biden is at 13% and Bloomberg is at 12%. Sanders' support in the state has climbed 15 points since December, while Biden's has slid eight points. Bloomberg has gained seven.

Decisive wins for a single candidate in California and Texas — states which will award more than 600 of the 1,991 delegates needed to secure the Democratic nomination — could change the tenor of a race that has at times seemed headed for a protracted fight.