Representative Kyrsten Sinema’s upset victory in Arizona on Monday night marked the first time a Democrat has been elected to the Senate from that state since 1988. Here are six takeaways about the race and the changing nature of Arizona politics.

[Catch up on Ms. Sinema’s victory remarks and the reaction in Arizona.]

A political realignment is possible

With Republican politics in Arizona looking less like the brand practiced by senators like John McCain and Jeff Flake — independent-minded, relatively bipartisan at times — many centrist voters in the state’s G.O.P. are increasingly politically homeless.

That has had an impact in suburban areas like vote-rich Maricopa County, which includes Phoenix. Mr. McCain and President Trump both carried the county in 2016, but Ms. Sinema was ahead there by nearly four percentage points over the Republican candidate, Representative Martha McSally.

Ms. Sinema’s win signals that a political realignment in Arizona is possible for federal offices. Hillary Clinton lost the state in 2016 by about 3.5 percentage points; Ms. Sinema was a different kind of candidate, with a different message, and she won statewide by about 1.7 points.