President Trump will move within days to nominate his third Supreme Court justice in just three-plus short years — and shape the court for literally decades to come, top Republican sources tell Axios. Driving the news: Senate Majority Leader Mitch McConnell and Senate Republicans are ready to move to confirm Trump's nominee before Election Day, just 46 days away, setting up one of the most consequential periods of our lifetimes, the sources say.What they're saying: "In the last midterm election before Justice Scalia’s death in 2016, Americans elected a Republican Senate majority because we pledged to check and balance the last days of a lame-duck president’s second term. We kept our promise. Since the 1880s, no Senate has confirmed an opposite-party president’s Supreme Court nominee in a presidential election year," McConnell said in a statement."By contrast, Americans reelected our majority in 2016 and expanded it in 2018 because we pledged to work with President Trump and support his agenda, particularly his outstanding appointments to the federal judiciary. Once again, we will keep our promise.""President Trump’s nominee will receive a vote on the floor of the United States Senate."Why it matters: We know Trump's list of potential nominees, we know the process, and we fully know the politics set to explode. Republicans, assuming they stay united as they have through thick and thin, hold all the cards. A Democrat involved in the machinations tells us: "[U]ltimately if their caucus hangs together, you can't block them."Within moments of the news breaking, a top Democrat texted: "Catastrophe."The other side: Senate Democratic Leader Chuck Schumer plans to fight the nomination. In a statement dictated to her granddaughter days before her death, Ginsburg said: "My most fervent wish is that I will not be replaced until a new president is installed."Between the lines: The Senate Republicans' precedent of stonewalling Merrick Garland, after he was nominated by President Obama in 2016 — and the reported desire of Justice Ginsburg to be replaced only after a new president is installed — will do nothing to slow or sway Trump or McConnell, the sources tell us.A Republican close to the White House told Axios that if Trump and McConnell didn't move before the election, "the Republican base will revolt, sit home."The confirmation vote would be tight. Sen. Susan Collins (R-Maine) told the N.Y. Times' Jonathan Martin earlier this month that she wouldn't seat a Supreme Court justice in October: "I think that’s too close, I really do."