Democrats Are Spending More on the Ground in Key Senate Races

With a strong possibility that Democrats could lose control of the Senate in the midterm elections, they are investing heavily in voter turnout efforts.

In states too close to call like Alaska, Colorado, Iowa and North Carolina, Democrats are making much greater investments in the ground game than Republicans.

Not all spending is captured in Federal Election Commission data, but the spending trends are clear. The Democrats' spending advantage is greatest in states where they've had time to organize and plan for competitive races, and they are using that edge to register new voters; publicize absentee and early voting options; and, of course, make sure supporters actually go to the polls on Election Day. The efforts extend to states where the Republicans more recently made Senate contests more competitive, like Michigan.

Democrats have invested several million dollars in both North Carolina and Colorado for this ground game. Republican spending in those states so far has tended to focus on broadcast advertisements and direct mail.

That edge extends to Alaska, where the Democratic incumbent Mark Begich faces Dan Sullivan. Combined, Democratic independent groups, party committees and Mr. Begich's campaign have already spent nearly 10 times more than Republicans on wages and expenses for local staffers; get-out-the-vote efforts; and other field operations.

The state Democratic Party alone has spent at least $763,687 on voter turnout and staffing this year, which amounts to $1.45 for every citizen over 18 in the state. By comparison, the more than $1 million the Wake County Democratic Party has spent on voter turnout and staffing in North Carolina this year works out to 15 cents for every potential voter.

In Iowa, the state Democratic Party has spent more than $872,000 in ground operations, part of a substantial advantage that Democrats have over Republicans in that state. The party has paid the salaries of at least 148 people in the current election cycle, according to data through the end of August. The Republican Party of Iowa had 11 people on its federal campaign payroll in August.

The Republican candidate Joni Ernst had spent less than $40,000 on paid staff through June. Ms. Ernst faces Representative Bruce Braley in the race to succeed Tom Harkin, a Democrat who is retiring. Iowa remains a tossup race, according to Leo, The Upshot's Senate forecasting model, with Ms. Ernst taking the lead in the latest polls.

Michigan is a rare exception. There the two state parties have spent roughly similar amounts on staff through the end of August. Democratic outside spending on field operations has been less than in other key states, while Republicans have invested in field spending.

The Upshot determined ground game totals by adding up itemized expenditures on non-Washington staffers and spending specifically described as being for in-person voter contact and canvassing purposes. This includes mileage and per diem expenses for field staff and a few other smaller items like materials for door-to-door campaigning. The largest amounts went to campaign staff.

This isn't a perfect measure because some descriptions of spending are vague or include different categories, and not every staffer is engaged in voter contact. In addition, candidate spending is through June 30, while party spending covers this year through the end of August, and independent expenditure data includes general election spending through late September. Taken as a whole, however, the Democratic lead in this area is clear.

Outside groups working on behalf of Democratic candidates have extended the advantage. Super PACs, environmental organizations and abortion rights groups have spent more than $4.8 million on ground activity in Senate races in Alaska, Colorado, Iowa, Michigan and North Carolina. Republican-leaning groups have kicked in only $369,000.

The amount spent to help G.O.P. candidates doesn't include field work by Americans for Prosperity and other political nonprofits that do not have to report their spending. Americans for Prosperity does report some of its broadcast advertisements, but Federal Election Commission rules do not require disclosure of ground operations or direct mail. Although much of its spending represents broadcast ads, it also has more than doubled its field staff compared with the 2010 elections. Even if it decided to spend several million dollars in a race, it could not coordinate its work with a party or campaign (the same rule applies to super PACs). A spokesman for Americans for Prosperity did not respond to a request for comment.

The Democrats' advantage in field work investment doesn't guarantee victory in any of the closest races, and the continued focus on television and radio spending by Republicans and their backers may be enough to carry them to a Senate majority in an electoral climate favorable to them.

In Alaska, Colorado, Iowa and North Carolina, the number of network television spots is split roughly evenly between the two sides, according to data compiled by Echelon Insights, a Republican digital consulting firm. In Michigan, the number of ads favors the Democratic candidate, Representative Gary Peters, by a 70-30 margin over his opponent, Terri Lynn Land, the former Michigan secretary of state.

Spending on field operations is still a fraction of the amount that goes to television and other forms of advertising, and campaigns are reluctant to take money away from trying to reach mass audiences, even if it's unclear in many cases how many persuadable voters broadcast advertisements reach.

During the past week, at least two Republican super PACs reported spending more than $1.3 million on television ads opposing Mr. Peters. The Conservation Voters of Michigan, meanwhile, reported more than $245,000 in payments for canvassers supporting Mr. Peters through door-to-door contact.