CHEYENNE, Wyo. - Conservatives who say welfare recipients should have to pass a drug test to receive government assistance have momentum on their side.

The issue has come up in the Republican presidential campaign, with front-runner Mitt Romney saying it's an "excellent idea."

Nearly two dozen states are considering plans this session that would make drug testing mandatory for welfare recipients, according to the National Conference of State Legislatures. And Wyoming lawmakers advanced such a proposal this week.

Driving the measures is a perception that people on public assistance are misusing the funds and that cutting off their benefits would save money for tight state budgets - even as statistics have largely proved both notions untrue.

"The idea, from Joe Taxpayer is, 'I don't mind helping you out, but you need to show that you're looking for work, or better yet that you're employed, and that you're drug and alcohol free,"' said Wyoming Republican House Speaker Ed Buchanan on Friday.

Supporters are pushing the measures despite warnings from opponents that courts have struck down similar programs, ruling that the plans amount to an unconstitutional search of people who have done nothing more than seek help.

"This legislation assumes suspicion on this group of people. It assumes that they're drug abusers," said Wyoming Democratic Rep. Patrick Goggles during a heated debate on the measure late Thursday.

The proposals aren't new, according to the NCSL. About three dozen states have taken up such measures over the years.

But as lawmakers seek new ways to fight off the effect of the recession on state budgets and Republican politics dominate the national discussion as the party seeks a presidential nominee, the idea has sparked political debates across the nation.

This year conservative lawmakers in 23 states from Wyoming to Mississippi - where lawmakers want random screening to include nicotine tests - are moving forward with proposals of their own.

Romney, in an interview this month in Georgia, supported the idea. "People who are receiving welfare benefits, government benefits, we should make sure they're not using those benefits to pay for drugs," Romney said to WXIA-TV in Atlanta.

Newt Gingrich addressed the topic with Yahoo News in November, saying he considered testing as a way to curb drug use and lower related costs to public programs.

"It could be through testing before you get any kind of federal aid - unemployment compensation, food stamps, you name it," he said.

In Idaho, budget analysts last year concluded that such a program would cost more money than it would save, prompting lawmakers to ditch the idea.

Also, recent federal statistics indicate that welfare recipients are no more likely to abuse drugs than the general population.

Data show that about 8 percent of the population uses drugs. And before a random drug testing program in Michigan was put on hold by a court challenge, about 8 percent of its public assistance applicants tested positive.

In years past such legal challenges had a chilling effect on state legislatures, but that seems to have thawed.

Michigan's program was halted after five weeks in 1999, eventually ending with an appeals court ruling that it was unconstitutional.

For more than a decade, no other state moved to implement such a law.

"The biggest piece that has held up action now and in the past are the constitutional questions," said Rochelle Finzel, the Children and Families Program manager at the NCSL.

But Florida last year passed legislation that was eventually halted by a federal court ruling that cited constitutional concerns.

Finzel said some states are trying to avoid court challenges by requiring drug tests only in cases where there's reasonable cause to believe there's substance abuse, instead of requiring everyone to take a test.

Missouri took that approach in passing a law last year that hasn't gotten tied up in court, but which has touched off an attempt at political one-upsmanship from a House Republican who introduced a bill this month that would require his colleagues at the state Capitol to take and pass the same test.

In Wyoming, the Republican-controlled state House handily approved a welfare drug testing bill after a fiery debate Thursday. The plan sailed through a second vote Friday and needs only one more reading before heading to the solidly-conservative state Senate, where a key leader supports the concept.

In Colorado, a testing plan is expected to fail because Democrats who oppose it control the state Senate - but Republicans have succeeded in starting a conversation on the issue.

"If you can afford to buy drugs, and use drugs, you don't need" welfare, said Republican Rep. Jerry Sonnenberg, who is sponsoring a bill this session.

Sonnenberg said his bill also seeks to help drug users get clean because applicants must complete rehab to qualify for government aid again.

Sonnenberg's critics said the idea feeds off the negative - and unsubstantiated - stereotype that low-income communities are more likely to use drugs. Sonnenberg said he's not picking on any group, and pointed out that the legislation would likely have a narrow effect.

"The five percent, or the four percent, or whatever that percentage is that is on drugs, will have a choice to make. They will either do what they can to get clean, or not have their (Temporary Assistance for Needy Families) funds," he said.

In Wyoming, Republican Rep. Frank Peasley, a co-sponsor of the testing bill, said the measure is an effort to rein in a welfare system run amok.

"We are going broke," he said,

But Linda Burt, director of the ACLU in Wyoming, said this week it's possible her group would challenge the testing program if it's adopted in Wyoming.

"We challenged it in Michigan. We challenged it in Florida. Both of those cases found that singling out this particular group of people for drug testing was unconstitutional with absolutely no cause."

Associated Press writer Ivan Moreno contributed reporting from Denver.