(CNN) -- Brett Kavanaugh is set to become the Supreme Court justice who inaugurates a conservative majority for a generation, after wavering Republicans closed ranks to give him sufficient votes for confirmation in a historic victory for President Donald Trump. The final Senate vote is expected Saturday, but enough senators have committed to backing him after a tumultuous political battle inflamed by allegations by California professor Christine Blasey Ford that Kavanaugh sexually assaulted her when they were teenagers in the early 1980s. A dramatic and draining showdown that held Washington in thrall for weeks finally moved towards resolution when Maine Sen. Susan Collins -- the last undecided GOP senator -- said in a combative speech on Friday afternoon that she would vote to confirm Kavanaugh, after concluding there was not sufficient corroboration for Ford's claims. Despite being a key player in the most partisan confirmation process in decades, Collins said she hoped Kavanaugh, a former political operative in the George W. Bush White House, would work to depoliticize the court. Bush, in fact, had spoke repeatedly to Collins over the past few weeks and reassured her about his character and temperament, a person familiar with the conversations says. "So that public confidence in our judiciary and our highest court is restored. ... I will vote to confirm Judge Kavanaugh," Collins said, in a 40 minute speech.