With Hillary Clinton taking the lead in the competition for Democratic delegates, rival Bernie Sanders is vowing to fight on, saying on Monday that he has no plans of leaving the race anytime soon.

Sanders downplayed Clinton's weekend victory in Nevada, pointing out that the win only resulted in her picking up four additional delegates, out of the 2,383 needed to win the nomination. He says his campaign has plenty of time to make up lost ground.

"This is about a slog, state by state by state," he said. "Even if we do well, Secretary Clinton will get a lot of delegates and we'll just have to keep moving on."

Clinton pulled ahead of Sanders late Monday, when she eked out the final delegate from Saturday's Nevada caucuses, giving her a total of 52 caucus and primary delegates. Sanders has 51.

"HRC now takes (national) delegate lead," tweeted Clinton spokesman Brian Fallon. "Not planning on ever giving it back."

The milestone is important because once a candidate establishes a sizable delegate lead, it can be hard for opponents to make up the lost ground.

Eight years ago, then-Illinois Sen. Barack Obama outgunned Clinton for the party nomination by establishing a 100 delegate advantage that she was never able to overcome. Clinton's team, who hired Obama's former aides to run their delegate effort, hopes to copy his strategy this spring by parlaying their strength with African-American voters into a string of wins in South Carolina, on Feb. 27, and the southern contests that follow on March 1.

There are more than 1,400 delegates at stake in states such as South Carolina, Georgia, Alabama, Tennessee and Louisiana, and depending on the outcome and proportional allocation of delegates, Clinton could build a comfortable lead.

She also maintains a commanding lock on the party's leadership. An Associated Press survey of superdelegates, who are influential in picking the nominee, found that 449 of the party insiders back Clinton, while only 19 support Sanders. Those superdelegates can switch candidates and Sanders team says that if the count is close, they plan to lobby delegates from the states he wins to change their positions.

Sanders argues that she's made gains by lifting much of his message, saying she's adopting not only his policy positions but his "phraseology."

"I saw a TV ad and thought it was me, but it turns out it was Secretary Clinton in the ad," he said. "People of the United States need to know the difference between hastily adopted campaign rhetoric and the real record and the long held ideas of the candidate"