Election Cycle Emerges as the Year of the Pledge, but Some Candidates Resist

This is the year presidential candidates are being asked to take the pledge.

They are asked to state their opposition to abortion rights. They are pressed to pledge support for a constitutional amendment to balance the budget.

They have been asked to oppose pornography, women in combat and Sharia law — all part of a “marriage vow” pledge.

Candidate pledges, an incidental part of past presidential elections, have exploded this year as advocacy groups seek to hold a future Republican president accountable.

Driven by the same anti-Washington fury that delivered scores of new Republicans to the House last year, the pledges aim to impose litmus tests on candidates and discourage them from altering positions later under political pressure.

full: http://www.nytimes.com/2011/07/17/us/politics/17pledge.html