round. mitt romney made a big move toward winning the republican presidential nomination last night notching five primary wins. nbc s brian moore reports. reporter: if there were any doubts mitt romney was going to be the republican nominee, he erased them tuesday night with a clean sweep in connecticut, delaware, new york, pennsylvania, and rhode island. i can say with confidence and gratitude that you have given me a great honor and solemn responsibility. and together we are going to win on november 6th. reporter: rick santorum, who dropped out earlier this month, stopped just short of endorsing romney on cnn. so it s very clear that he s going to be the republican nominee and i m going to be for the republican nominee. reporter: newt gingrich didn t drop out but tipped his hat to romney. it s a night that he has worked hard for for six years and if he does end up as the nominee, i think every conservative in this country has to be committed to defeating