It’s hard to imagine a more eventful week-and-a-half in American politics.

July 13 — A young man with a rifle attempts to kill presidential candidate Donald Trump. Trump is slightly injured, but three people in the crowd are hit, one of them fatally.

July 15-18 — At the Republican National Convention in Milwaukee, delegates choose Trump as the party’s presidential nominee and accept Trump’s choice for vice president, J.D. Vance, by acclamation. Trump, wearing a bandage over his wound from the assassination attempt, gives a long but rousing speech accepting the nomination.

July 17 — President Biden tests positive for Covid-19. His illness adds to concerns about his age that have grown rapidly since his poor performance in a June 27 debate against Trump.

July 21 — Sen. Joe Manchin calls for Biden to leave the presidential campaign in favor of someone younger. Manchin is an independent who left the Democratic Party earlier this year, but he follows 36 Democrats in the House or Senate who have publicly suggested Biden should let someone else run for president.

July 21 — Later the same day, Biden announces his withdrawal from the presidential campaign and endorses his vice president, Kamala Harris, as the Democratic nominee.

July 22 — Polls suggest Harris has enough delegates to claim the nomination.

It’s another month before the Democratic National Convention opens in Chicago (Aug. 19-22). Whether Harris becomes the Democratic nominee then will be decided over those four weeks. When the convention closes, it’ll be 75 days until Election Day.

That’s not a lot of time for Democrats to attract enough support to defeat Trump, who one could argue has been running for the presidency nonstop since 2015. They’ll need to quickly unify behind a candidate, whether it’s Harris or someone else, and they’ll have to present a platform that independents and never-Trump conservatives can support. Those are both tall orders.

Last week could have started with a horrendous tragedy — for America in general and the Republican Party in particular — but 10 days later, Republicans look to be in great shape.