The U.S. Chamber is accelerating its voter education activities in key states this week, doubling down with new television ads in Ohio and Montana.

The Ohio ad, titled “Stop Hiding,” highlights Sen. Sherrod Brown’s (D) dismal 9% voting record with the U.S. Chamber. The ad refers to Brown’s support for increased energy taxes and his vote for the 2010 health care law.

Separately, the Montana ad, titled “500 Billion,” takes aim at Sen. Jon Tester’s (D) vote in favor of the health care law and the $500 billion in new taxes necessary to pay for it The 30-second ad urges voters to “call Jon Tester and tell him Montana deserves better than higher taxes and lost jobs.”

Tester is currently running in a closely watched race against Republican Rep. Denny Rehberg. Brown is expected to square off against Ohio State Treasurer Josh Mandel (R) in what is sure to become one of the most hotly contested and most expensive races in 2012.

The U.S. Chamber plans to play a major role nationwide in the 2012 elections, educating voters about candidates who have demonstrated consistent support for America’s job creators and who will work to advance a pro-growth agenda in Congress and those who won’t. The Chamber seeks to capitalize on its electoral successes of 2010 with an “Advance and Protect” strategy in 2012: advance its interests in the Senate and protect the pro-growth gains in the House.

The Montana and Ohio ads are the second set of ads to run in those two key states. The previous ads were part of a recently launched six-state ad campaign that includes Iowa, Nevada, Pennsylvania and Washington.

Says Rob Engstrom, Senior Vice President and National Political Director, “Votes, not words, are what matter most to the business community, and the Chamber will engage earlier and stronger than ever before to highlight the difference between candidates who support free enterprise policies and those who have supported bigger government and more regulation.”

The Chamber’s ads can be viewed here.