Senator Barack Obama claimed a historical victory on Tuesday evening, following the final primaries in South Dakota and Montana. The votes he picked up in these states as well as a surge of superdelegate support helped him surpass the 2,118 delegate mark—the amount needed to win the nomination at the Democratic convention later in the summer. Senator Hillary Clinton is expected to throw in the towel and endorse him this Saturday.

“Tonight, we mark the end of one historic journey with the beginning of another — a journey that will bring a new and better day to America,” said Obama at his victory speech.

The Illinois Senator’s win concludes a Democratic primary that broke several records - most voter turnout, most money raised and the longest such contest to date, staying in the public eye for about eighteen months. It was also the first time that the frontrunners of the party were not white men. Obama now has the distinction of being the first black nominee of a major party and potentially, the first black president.

The Democrats can now focus their energy on their main opponent – Senator John McCain, the Republican nominee. Clinton’s critics suggested that her earlier hesitancy to withdraw, despite the mathematical impossibility of overtaking Sen. Obama, was an obstacle impeding the unity that the Democratic party needs in order to win against McCain. American history offers many examples of reform movements and political candidates whose momentum slowed because of splintered support.

There is also the looming question of whether Obama will offer Sen. Clinton the vice presidential spot on his ticket. He had several times mentioned that Clinton and he would be working closely, whatever that may mean. The Obama campaign had not confirmed any speculations about his choices for a running mate.

Words by Erica Block and Igor Kossov.