Washington (CNN) -- Idaho on Wednesday became the first state to pass a law saying no thanks to part of President Obama's health care proposal.

The Idaho Health Care Freedom Act says in part, "every person within the state of Idaho is and shall be free to choose or decline to choose any mode of securing health care services without penalty or threat of penalty."

Gov. C.L. "Butch" Otter, a Republican, said Wednesday he signed it because he believes any health care laws should ensure people are "treated as an individual, rather than as an amorphous mass whose only purpose in this world is to obey federal mandates."

Several other states may follow suit.

The governor of Virginia is expected to sign a bill passed in his state last week, and according to American Legislative Exchange Council, similar proposals have made it through one chamber of the legislatures in Missouri, Oklahoma and Tennessee. While such bills have recently failed in six states, 22 additional states have seen proposals introduced.

These state laws would directly conflict with the national health care bill that Democrats are trying to pass, which includes a requirement that all individuals get health coverage or face a tax penalty.

Several legal analysts said if Congress enacts a national health care law, it would supersede any state laws written to block them.

"I think most of the states that are passing these laws understand that they can't trump federal law with state law," said Professor Jonathan Siegel at George Washington University Law School. "But what they get out of it is symbolic effect. They're sending a message to the federal politicians that they don't like the health care mandate."

Such state laws might not be the only legal challenge to Democratic health care legislation.

Florida Attorney General Bill McCollum, a Republican, on Tuesday sent a letter to the other 49 state attorneys general, asking them to join him "in preparing a legal challenge to the constitutionality of whatever individual mandate provision emerges, immediately upon the legislation becoming law."

States have previously challenged federal laws and regulations in areas aside from health care.

Five states have passed a Firearms Freedom Act, according to firearmsfreedomact.com, including Montana, Wyoming, South Dakota, Tennessee and Utah. The law declares that any guns that are manufactured and kept in-state are not subject to federal gun laws passed by Congress under interstate commerce authority, because the guns never crossed state lines.

A number of states have also passed laws trying to wrest more control from Washington over issues such as how public lands are used or how a state's National Guard forces are deployed overseas, according to the 10th Amendment Center, which advocates for states' rights.

While such laws may face an uphill path in court, supporters describe them as a sign of public opinion, which can still have impact.

They point to last year's announcement of federal policy on medicinal marijuana, after 14 states passed laws to allow its use. While federal drug law makes no exception to allow medicinal use of marijuana, Attorney General Eric Holder said in October that prosecuting the use of medicinal marijuana users wouldn't be a priority.

He said the Justice Department would instead "effectively focus our resources on serious drug traffickers, while taking into account state and local laws."

CNN's Brian Todd and Eric Weisbrod contributed to this report.