It’s not just Senate Democrats playing defense across the 2012 map — President Barack Obama’s team will spend millions on a wide playing field of states the Democrat won in 2008.

Several of those states also have competitive Senate and House contests that will generate tons of attention. That means massive coordinated campaigns from both parties are likely to flood the airwaves with ads and swarm the streets with volunteers.

Presidential coattails often become a factor in House races, and both parties are counting on the elevated turnout of a presidential cycle to help them in marquee matchups.

Here’s a look at the 2012 battleground’s hottest spots, with a focus on states where the presidential race will overlap with the fight for control of Congress.

Colorado

Democrats say they are confident Obama can win again here, but that’s no given. There will be at least two House races to watch as Democrats try to unseat GOP freshmen, but without a Senate race on the ballot (not to mention the Democratic National Convention) this state is unlikely to receive the same attention it got in 2008.

Florida

Team Obama has made the Sunshine State central to its 2012 strategy. The thinking is that demographic shifts have added thousands of Latinos to the voter rolls and that if he wins here, he wins a second term. Sen. Bill Nelson (D) began the cycle looking like a prime target for the GOP. But he looks pretty strong one year out, and the late and crowded GOP primary is likely to delay the official start of the Senate contest until just after the Republican National Convention wraps up in Tampa in September. Florida is adding two House seats that Democrats want to claim, and GOP freshmen who won in last year’s wave are likely to star in the most competitive House races. With Sen. Marco Rubio (R) expected to at least appear on vice presidential short lists, Florida will receive no shortage of attention.

Iowa

The state that launched Obama’s rise to the presidency was a nice boost to his 2008 Electoral College total, but it’s far from a given that he’ll win it again. The GOP nominee will likely have an organizing advantage following the competitive caucuses that kick off the presidential campaign. There are three House races to watch, including a Member-vs.-Member clash, and any Obama investment in the Hawkeye State will fuel the Democrats in those contests. But Iowans disappointed in the president could easily return this state to the GOP column (George W. Bush won it in 2004) come November.

Michigan

The lousy economy is one reason this state remains one to keep an eye on, and if former Massachusetts Gov. Mitt Romney is the GOP nominee, it could get another look. Sen. Debbie Stabenow (D) looks to be in fairly good shape to be re-elected, but both parties are keeping a close eye on how her race develops. Redistricting has complicated matters for House Democrats, who will be fighting to take back at least one of the two seats that fell to the GOP last year.

Nevada

Democrats have their sights on two House seats, aiming to unseat freshman Rep. Joe Heck and win a new seat in the Las Vegas area. The president will try to re-engage with the vast network his team built in 2008 — the same one that helped Senate Majority Leader Harry Reid hold on to his seat in a tough 2010 fight. If it’s a good night for Obama, Rep. Shelley Berkley (D) might be elected as the next Senator. This is another state where Latino voters could boost Democrats.

New Hampshire

The Granite State tends to get caught up in electoral waves, with its two-seat House delegation turning over completely in 2006 and again last fall. Democrats will spend big to try to unseat those two House Republicans, but the GOP could put this state in play if Romney, former governor of neighboring Massachusetts, is the party’s presidential nominee. And the Republicans could also have an advantage here given all the time they are spending campaigning ahead of the first-in-the-nation primary.

New Mexico

Obama won here in a landslide, but a competitive open-seat Senate race and 2010 GOP gains at the state level will make victory tougher this time around.

North Carolina ­

This state is critical to Obama’s re-election strategy, and that’s one reason he’ll hold the Democratic National Convention in Charlotte next summer. There’s no Senate race, but thanks to redistricting, the House contests will be rough on Democrats because four Blue Dogs were drawn into substantially Republican turf.

Ohio

As it is in every national election, this is ground zero for Democrats. Team Obama will compete fiercely here, as Sen. Sherrod Brown faces a competitive race against an up-and-coming young Republican. Democrats will try to win back some of the five House seats they lost in 2010. But with a GOP-drawn House map and a two-seat loss due to reapportionment, it will be a nasty, expensive slog to Election Day.

Pennsylvania

If the president can’t win here, it’s game-set-match for the GOP. Expect a lot of spending from outside groups as Republicans try to make the Keystone State competitive. Democrats will try to gain back some of the territory (four House seats) they lost in 2010, but much depends on the yet-to-be-determined map. Sen. Bob Casey (D) looks comfortable as he tries for a second term, but if the presidential race really heats up here, he could be in for a bumpier ride.

Virginia

Obama was the first Democrat to win this state in four decades, and the president’s team has made it clear he’ll devote many hours to campaigning here in hopes of repeating his success. Senate races in the Old Dominion always take on national implications, and the open-seat battle between former Sen. George Allen (R) and former Democratic National Committee Chairman Tim Kaine will be the neck-and-neck race to watch to the finish. Also expect at least one competitive House race here as Democrats attempt to reclaim battleground territory they lost in 2010.

Wisconsin

As Wisconsin goes, so goes the nation. This perennial presidential swing state will be representative of the national mood. Democratic Rep. Tammy Baldwin will try to become the nation’s first openly gay Senator in what surely will be a competitive open-seat race, and Democrats will attempt to unseat two GOP House freshmen.

Long Shot: Arizona

Obama’s team fantasizes that this could end up being a competitive state for Democrats, just as party strategists hope to put the open-seat Senate race into play. The Democrats did little here in 2008 because it is Sen. John McCain’s home state, but as the president campaigns in the West, the Grand Canyon State is likely to get some extra attention. A new House seat thanks to population gains will help focus the parties on winning here.

Correction: Nov. 14, 2011

An earlier version of this article incorrectly identified when George W. Bush won Iowa’s Electoral College votes. Bush lost the state in 2000 and won it in 2004.