Both parties in Virginia have poured millions of dollars into television and radio advertising in the fight to control the state Senate, but some of that cash may have been wasted because of the structure of the Commonwealth’s legislative districts.

State senate candidates and committees from both parties have spent a grand total of $5.8 million in Virginia on broadcast, cable and radio advertising. Republicans hold the edge, having spent $3 million on advertising compared to $2.7 million for Democrats.

Democrats currently hold a four-seat majority in the state Senate, but their grip on power is tenuous given Virginia’s political climate. Moreover, they’ve had to defend districts where in past cycles the GOP didn’t even field a candidate. This year, the battle to control the state Senate been fought primarily in thirteen districts, which have been blanketed with ads.

Unfortunately for the candidates, the Virginia Legislature paid no attention to the geography of media markets when it drew up the legislative districts. The result is uniquely shaped boundaries that can spill-in and spill-out of several media markets at a time, making it difficult to efficiently reach the right voters through mass media.

Take the Roanoke media market, where candidates and issue groups together have spent $1.9 million. The map below illustrates how districts 20, 21, 22 and 38 spill-in and spill-out of the city’s TV market. In the case of districts 38 and 22, only voters from certain counties fall into the Roanoke market. Other voters who reside outside of the market are not exposed to the campaigns’ Roanoke advertising at all.

In districts where there is significant market spill-in and spill-out, campaigns must determine if a worthwhile percentage of their targeted voters will actually receive exposure to their broadcast ads.

For example, district 38 falls into three broadcast markets: Bluefield-Beckley, Roanoke and Tri-Cities. As the state’s biggest spender, state Sen. Phillip Puckett (D) — who didn’t face an opponent in 2007 — has placed over a half a million dollars on ads in these markets on broadcast and cable. Puckett has placed $545,000 on broadcast in all three markets and $26,000 on cable in Bluefield-Beckley only.

Adam Light, Puckett’s Republican challenger, has spent over $380,000 on advertising in Bluefield-Beckley, Roanoke and Tri-Cities. Light has placed $323,000 on broadcast, $53,000 on cable and $7,000 on radio. He has received additional $38,000 in advertising support from the Republican Party of Virginia on cable and radio.

This map shows district 38 and the counties that fall into each broadcast TV market.

To put this spending into context, here is a map of the district and each TV market to their full extent.

Despite his massive outlay, Puckett is in danger of losing his seat after 13 years in office. If he’s defeated on Tuesday, questions should be asked about the effectiveness of his advertising strategy.

As an alternative to the large scope of broadcast, advertising on cable TV allows candidates to more precisely target the voters within their districts. Instead of blanketing a whole media market with advertisements, campaigns can pick and choose which cable systems cover their district. The drawback to advertising on cable, however, is that the audience is a lot smaller.

Total Spend by District
At least thirteen state senate districts have been blanketed with ads: VA SD-01, VA SD-06, VA SD-09, VA SD-17, VA SD-20, VA SD-21, VA SD-22, VA SD-29, VA SD-36, VA SD-37, VA SD-38, VA SD-39 and VA SD-40.

Total Spend by Candidate

Total Spend by Market
Where in Virginia have these campaign dollars been spent? Candidates and issue groups together have spent $1.9 million in Roanoke, $1.6 million in Washington, DC, $890k in Norfolk, $498k in Tri-Cities, $413k in Richmond, $377k in Charlottesville and $135k in Bluefield-Beckley.

A version of this blog post was published on Campaigns and Elections blog, Campaign Insider