Senator Bernie Sanders won Colorado while former vice president Joe Biden scored a victory in Oklahoma and Tennessee during Super Tuesday’s Democratic presidential primaries as the 2020 nominating contest inches closer to becoming a two-man race.

Biden added Oklahoma with its 37 pledged delegates to his list of wins Tuesday evening. The former national front runner has also won the Virginia, North Carolina, Alabama and Tennessee primaries.

Sanders has also won his home state of Vermont as well as Colorado with its 67 pledged delegates.

Voting is still occurring in Texas and California, the two most delegate-rich states that account for 415 and 228 delegates respectively.

Sanders currently leads Biden by a sliver in national polls, 26 percent to Biden’s 24 percent, according to the RealClearPolitics average of polls.