Gay marriage bans in four states will be significantly tested Wednesday when a three-judge panel will hear arguments on challenges to the laws — the latest in a slew of lawsuits against similar laws nationwide since last summer.

The U.S. Court of Appeals for the Sixth Circuit in Cincinnati will hold a marathon session regarding six lawsuits seeking to strike down laws in Kentucky, Michigan, Ohio and Tennessee that bar same-sex marriages. District court judges already have ruled the laws unconstitutional.

Since the Supreme Court last year struck down a key part of the federal Defense of Marriage Act, there have been 19 federal court rulings across the country against same-sex marriage bans — 16 at the district court level and three circuit court decisions upholding district court rulings.

More than 70 cases have been filed in all 31 states that prohibit same-sex marriage. Nineteen states and the District of Columbia allow such marriages.

Circuit courts will hear arguments in gay marriage bans later this summer in Indiana, Wisconsin, Idaho and Nevada. Texas has asked the Firth Circuit Court to appeal a lower court’s ruling against the state’s gay marriage ban, but no date has been set.

The rulings have gay marriage proponents hopeful the Supreme Court soon will revisit the issue and render decisive blow against all same-sex marriage bans.

“What we’ve seen over the last year in court rulings from Idaho to Indiana is exactly the same as what’s happening around kitchen tables all across the country,” said Chad Griffin, president of the Human Rights Campaign, the nation’s largest gay-rights advocacy group. “Americans know that its wrong to tell two people in love they can’t get married, just because they’re gay or lesbian.”

“We believe the couples and their incredible attorneys challenging these bans (in the Sixth Circuit) will prove that the state you call home should never determine your ability to marry the person you love.”

But two of the panel’s three judges were appointed by Republican President George W. Bush, giving conservatives who support the gay-marriage bans hope that their side will prevail. The third judge is an appointee of President Clinton.

“The Sixth Circuit needs to follow the law and reject imperious arguments that would whimsically overturn the electoral decisions of the citizens of those four states,” said Tony Perkins, president of the socially conservative Family Research Council. “They have already decided that marriage should be reserved to the union of one man and one woman. This was not a bizarre choice.”

The panel is expected to issue its decision later this year.

Last week a federal appeals court in Virginia ruled the state's same-sex marriage ban was unconstitutional.

The ruling had an immediate ripple effect, as North Carolina Attorney General Roy Cooper said hours later that, because of the decision, his office no longer would defend his state's voter-approved ban on same-sex marriage in court.

Because the Richmond, Va.-based circuit court has jurisdiction over North Carolina, Cooper said it was likely his state's ban would be overturned and opposing the lawsuits challenging it would be "futile."

The Supreme Court's 5-4 ruling on DOMA last year prohibited the federal government from denying benefits to same-sex couples who are legally married.

Social conservatives have downplayed the ruling, stressing it doesn't give gays and lesbians the constitutional right to marry, and vowed to continue to fight the growing gay-rights movement.