From NBC's Pete Williams
Wyoming political sources say Gov. Dave Freudenthal will announce today that he will not run for a third term.
The two-term Democrat is hugely popular, winning re-election in 2006 by the largest margin in state history. His high approval ratings are especially surprising in a staunchly Republican state.
The Wyoming governorship will now almost certainly switch back to Republican control. No Democrats in the state have anything approaching Freudenthal's popularity. Republicans who have already announced their candidacies include Matt Mead, grandson of former Wyoming Sen. Cliff Hansen. Another who may now get into the race is state House Speaker Colin Simpson, son of former Wyoming Sen. Al Simpson.
Had Freudenthal decided to run again, he would have faced a state law limiting the state's top elected officials to two terms. But it was expected that he could have successfully mounted a challenge to the law under the state constitution. The Wyoming Supreme Court earlier invalidated a term limit for state legislators.