This map shows where statehouse battleground campaigns are playing out 

While national media attention has focused heavily on congressional midterm elections, the odds are much better that the candidate knocking on your door is running for a seat in your state's capital.

In 46 states, voters this year will choose some 6,066 state legislative seats that are up for regular elections — about 82 percent of all statehouse seats.

Eighty-seven out of the nation's 99 state legislative chambers are up for grabs this November. (There are only 99 because Nebraska is the lone state with a single-body, or unicameral, legislature. The rest have upper and lower chambers like Congress.)

Thirty-six states are holding governors' races, and nine of those are considered toss-ups or possible flips by analysts at the Cook Political Report — Alaska, Connecticut, Florida, Iowa, Maine, Michigan, Nevada, New Mexico and Wisconsin.

While the governors' races have been handicapped by political analysts, the outcome of state legislative races is much more difficult to predict. That's in part because voter opinion polls are rarely commissioned for individual statehouse races. And these state legislative races are often decided by just a few hundred votes.

This year, the battlegrounds tend to be in states where control of the governor's office is up for grabs. In the 36 states that are electing governors, half of them are open races because the incumbent retired, failed to win the party nomination or reached the term limits set in that state. Legislatures where Democrats or Republicans hold slim majorities include the state senates in Colorado, Connecticut, Delaware, Maine, Nevada, New York and Washington, along with single-digit lower chamber majorities in Connecticut, Maine, New Mexico and Washington.

Like this year's national congressional races, Republicans have more to lose at the state level than Democrats. Having gained ground in three out of the last four election cycles, Republicans control both the state house and senate chambers in 25 states; Democratic control just seven, 17 more are split.

But the "blue wave" Democrats are hoping for on the national level may well extend to state houses across the country. In past midterms, the party of the president has lost around 400 state legislative seats on average, according to the National Conference of State Legislatures.

Since 1902, the president's party has lost state legislative seats in 27 of 29 midterm election cycles. (The two exceptions were 1934 and 2002.) The last major rout at the state level happened in the 2010 midterms, when Democrats got what President Barack Obama called a "shellacking." Some 708 state house seats changed hands, more than in any election since 1966.

CNBC NEWSLETTERS

Get the best of CNBC in your inbox

Please choose a subscription

Please enter a valid email address
Get these newsletters delivered to your inbox, and more info about our products and service. Privacy Policy.