The Romney campaign has escalated its ad buying.

For a week starting this last Wednesday the Romney campaign has bought just over $12 million in broadcast and cable time in eight battleground states, according to a Democratic source tracking ad buys. That is a small increase from previous weeks.

Both the Obama and Romney campaigns are vigorously fighting for any advantage in Ohio, Florida and Virginia as evidenced by the fact a majority of the swing state ad money from both sides is going into these three states.

Analysts have said the Republican ticket must carry at least one if not more of these three key states in order to get to 270 electoral votes. Sweeping all three for the president will mean a much easier road to re-election.

As for the Romney campaign, here is a breakdown of its latest buy, according to the ad tracking source, spanning Wednesday through Oct. 2:

OH: $2.51 million

IA: $860,000

VA: $2.47 million

NC: $1.29 million

WI: $920,000

FL: $2.76 million

NV: $530,000

NH: $14,000