A pair of tea party groups is teaming up to pressure key Republicans to support an effort to defund Obamacare.

Tea Party Patriots and the grassroots group For America are launching online ads against a dozen GOP senators who either oppose the effort or haven't announced a position.

Along with the ads, leaders of the groups will embark on a six-state, five-day "Exempt America" tour (the idea being that the American people should be exempt from Obamacare) that will bring them to the home states of several of these senators.