Hillary Clinton has been declared the winner of the Missouri primary, locking Sen. Bernie Sanders out of any victories in the states that voted in primaries Tuesday.

The victory became official two days after polls closed in the state and does little to change the delegate count in the Democratic race.

But it represents a significant psychological boost for Clinton’s campaign as it marches ever closer toward the party nomination.

The campaign has believed for days that Clinton would ultimately be declared the winner in Missouri. In the end, Clinton’s margin in Missouri was just more than 1,500 votes, according to the most recent numbers released by the Missouri secretary of state’s office.

Sanders said in a statement Thursday that he would not request a recount of the state’s results because it would not be likely to affect the number of delegates awarded to the two candidates. “I would prefer to save the taxpayers of Missouri some money,” he said.

Democratic front-runner Hillary Clinton spoke to supporters in West Palm Beach, Fla., after primary voters took to the polls in five states: Florida, Illinois, Ohio, Missouri and North Carolina. (Reuters)

Almost 800 pledged delegates were up for grabs in the March 15 primaries. Clinton won by large margins in Florida, North Carolina and Ohio and edged Sanders in Illinois and now Missouri. Clinton expanded her lead over Sanders to more than 300 delegates, not including the superdelegates who are not bound to a candidate based on primary results.

Sanders has pledged to remain in the race and has said that upcoming contests in Arizona, Idaho, Utah and elsewhere pose opportunities for him to close the gap with Clinton.

In a memo Wednesday, Clinton campaign manager Robby Mook said that as a result of Tuesday’s primary results, “a string of victories by Sen. Sanders over the next few weeks would have little impact on Sec. Clinton’s position in the race.”

Clinton and Sanders face off next in Arizona, which holds its primary Tuesday. Sanders has campaigned in the state this week, and Clinton will campaign in Phoenix on Monday.

Southern dominance does not mean Trump and Clinton will win everywhere

Both sides have set Arizona up as an opportunity — for Clinton to continue her winning streak and for Sanders to regain momentum.