[3] In 2015, it launched a nationwide initiative calling for a convention to propose amendments to the United States Constitution to reduce federal spending.

[13] The IRS failed to turn over the list, filing a petition for a writ of mandamus from the appellate court so that it would not have to disclose information on groups the agency had targeted.

[14] In March 2016, a three-judge panel of the United States Court of Appeals for the Sixth Circuit issued a unanimous ruling rebuking the IRS and giving the agency two weeks to produce the names of organizations it had targeted based on their political leanings.

In August 2018, Judge Michael R. Barrett approved the $3.5 million settlement between the IRS and hundreds of tea party groups on "what all sides now agree was unwarranted and illegal targeting for political purposes.

Some members of both the Republican and Democratic parties have supported bills backed by the organization, while others from both the left and right have criticized the proposal, fearing that it could "set the stage for a runaway convention to make over the entire Constitution.

Many of them are turning to Article V."[3] In early 2020, amid the COVID-19 pandemic, the group began operating an online campaign called Open the States which helped organize opposition to government mandated stay-at-home orders.

Senator Tom Coburn (R) has endorsed the Convention of States Project and served as a senior advisor to CSG's efforts until his passing in 2020.

[9] In September 2014, CSG announced that a Legal Board of Reference had signed a "Jefferson Statement" endorsing the Convention of States initiative.

The Legal Board of Reference included Randy Barnett, Charles J. Cooper, John C. Eastman, Michael Farris, Robert P. George, C. Boyden Gray, Andrew C. McCarthy, and Mark Meckler.

[1][38] Liberal advocacy group Common Cause has been a vocal opponent of the CSG's Convention of the States initiative; in a May 2016 report entitled The Dangerous Path: Big Money's Plan to Shred the Constitution, the group wrote that "There is nothing to prevent the convention, once convened, from proposing additional changes that could limit or eliminate fundamental rights or upend our entire system of government.

[42] The group does not disclose the sources of its funding; in a 2013 tax filing, CSG stated that disclosure would "chill the donors' First Amendment right to associate in private with the organization.