UPDATE: Those who bet on a group effort were right. After a conference call with over a dozen states, Abbott posted the following update on Facebook:

“Just got off the AG conference call. We agreed that a multi-state lawsuit would send the strongest signal. We plan to file the moment Obama signs the bill. I anticipate him signing it tomorrow. Check back for an update at that time. I will post a link to the lawsuit when it is filed. It will lay out why the bill is unconstitutional and tramples individual and states’ rights.”

Here is the statement Abbott released after healthcare passed:

"The federal health care legislation passed tonight violates the United States Constitution and unconstitutionally infringes upon Texans' individual liberties. To protect all Texans' constitutional rights, preserve the constitutional framework intended by our nation's founders, and defend our state from further infringement by the federal government, the State of Texas and other states will legally challenge the federal health care legislation."

Abbott warns Texas and possibly other states could sue the federal government over the measure requiring nearly all Americans to buy insurance. The warning from Abbott, a Republican, comes as Congress enters the final stages of negotiations over the health care legislation, Democratic President Barack Obama's signature domestic initiative.

"It would require all citizens to buy something — in this case insurance — or face a tax penalty," Abbott wrote in a letter Tuesday to U.S. Sens. Kay Bailey Hutchison and John Cornyn, both Texas Republicans. "This unprecedented congressional mandate threatens individual liberty and raises serious constitutional questions."

Virginia will file suit against the federal government charging that the health-care reform legislation is unconstitutional, Virginia Attorney General Ken Cuccinelli's office confirmed last night.

Cuccinelli is expected to argue that the bill, with its mandate that requires nearly every American to be insured by 2014, violates the commerce clause of the U.S. Constitution. The attorney general's office will file suit once President Barack Obama signs the bill into law, which could occur early this week.