Badass Normal: Rube and Cole face people with power armor and mecha on foot with normal weapons.

Ax-Crazy: The Progressive Restoration movement.

Aircraft and artillery are next to useless in Urban Warfare mechs might have a maneuverability and elevation advantage over conventional ground vehicles, though.

They did, however, manage to successfully occupy New York City without any problem, so they couldn't have been too impractical. In the one major combat action shown, they get blown to bits by missiles from Apache helicopters before they even get into the mechs' weapon range.

Awesome, but Impractical: The Progressive Restoration's Mini-Mecha.

It's extremely sudden - taking all of one sentence - and undramatic.

Anyone Can Die: Rube, who was the protagonist up until he gets shot in the eye by his secretary.

Presidency for that November, and what was still in the future when the book was first published.

Alternate Universe: There are less-than-subtle hints that the story is meant to take place during the summer of 2008, during the heated race for the U.S.

Which brings up the question of why they assassinate a guy that would be out of office in a few months.

This is clued in not only by clear call-outs to modern devices and cars, but also to then-current Senators and specific calendar dates (the Friday 13th mentioned in the book fits with the calendar alignment) and the election cycle. Literally, it's 2008, about two years after the book was published.Also, there's no specific mention of who the President and other political figures are except by allusion.

20 Minutes into the Future: It's today… except with Mini-Mecha, Powered Armor, hovercraft, etc.It was followed with Hidden Empire in late 2009.

This has actually happened before, in several parts of the world, in the last couple decades, and Empire is the story of how it could happen in the 21st-century United States. Card takes a very serious look at the rising extremism and political tensions in modern America and extrapolates them to their logical conclusion: when both sides toss around enough 'they're going to destroy our way of life' rhetoric, someone on one side will start shooting, and then it becomes a matter of self-defense for everyone involved. Card was hired to write a story for the game, about a second Civil War, and the authors got more than they bargained for. Takes place in the same universe as the game Shadow Complex. A 2006 What If? novel by Orson Scott Card, telling the story of Major Reuben 'Rube' Malich and Captain Bartholomew Coleman, who get caught up right in the middle of the next American Civil War - the war between the Left and the Right.

Hidden Empire by Orson Scott Card