When it comes to media spending, Democrats Anthony G. Brown and Douglas F. Gansler are like distance runners intent on keeping their rival close. The two most visible candidates in the primary for governor each spent more than $2 million on television and radio advertising from early March until late May, according to documents and campaign interviews.

But there is a difference.

Trying to seize an advantage in the Baltimore battleground, Brown outspent Gansler by more than two-thirds on network broadcast stations in the Baltimore market. All of the Democratic candidates — Brown, Gansler and Del. Heather Mizeur — are from the Washington suburbs, so the Baltimore region has no hometown favorite.

"Yes, we have made a heavy investment in Baltimore," Brown campaign manager Justin Schall said. "I don't think it's a surprise to anyone. We are from Prince George's County and Doug Gansler is from Montgomery County and Heather Mizeur is from Montgomery County. Baltimore City and Baltimore County and all the surrounding areas are all very important areas for the state."

Gansler, on the other hand, has spent more than Brown on radio and cable stations in the Washington market. He has spent heavily on WTOP, an all-news radio station. And Gansler was on the air first in Washington, although the candidates' spending with Washington's major television stations are now almost the same.

Asked about the early push in Washington, Gansler strategist Bill Knapp said the campaign wasn't emphasizing one market over another. "We're executing a strategy that has both markets executing a critical role for us," Knapp said. "Both markets are equally concerned about taxes and jobs."

Mizeur's campaign plans to begin airing its first ad in Baltimore next week. Her campaign said the spot will be "introductory."

Broadcasters' political advertising invoices are publicly available and are regularly compiled by the campaigns and their professional media buyers. The campaigns, which sometimes disagree on the spending totals, regularly monitor each other's ad buys.

"Neither Brown nor Gansler wants to allow the other to get a leg up," said Martha McKenna, a partner in the Democratic media consulting firm McKenna Pihlaja.

She called Brown's Baltimore ad blitz "a very savvy move. None of the three candidates are from the Baltimore media market, so it makes sense to invest heavily to introduce yourself."

Ads placed in Baltimore are considered more efficient. That's because the Washington market is shared by Virginia and the District of Columbia, whose residents don't vote in Maryland.

Both campaigns say their messages are consistent across the two markets. Sometimes, however, an ad will run in Baltimore or Washington but not in the other location — at least not immediately.

That was the case when Gansler's campaign launched an ad last week criticizing Brown for not attending a televised debate on Baltimore's Fox 45. The ad, which mentioned the city by name, appeared in Baltimore.

Brown countered with an ad — for both markets — criticizing Gansler's plan to reduce the corporate income tax and not immediately fund full-day pre-kindergarten for all children.

Gansler's campaign says he favors pre-K but that it should be phased in — beginning with the neediest families — to make sure it's affordable and effective.

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