Like many gay couples in the United States, Theresa Volpe and Mercedes Santosof Chicago will be keeping a close eye on the Supreme Court this week as it hears arguments on two same-sex marriage cases.

The high court review coincides with a crucial moment at home in the couple’s fight to make Illinoisthe tenth state in the nation to legalize same-sex marriage. Volpe and Santos, who have personally lobbied Illinois lawmakers on this issue, worry about delays in drumming up enough votes for passage of a bill in their state and a growing campaign from opponents.

Supporters had hoped the bill would sail through the Democratic-majority legislature in President Barack Obama‘s home state in January. But it took until Valentine’s Day to go through the Senate and was still several votes short in the House by late March.

“What’s going on in Illinois is a little disturbing – we’re worried and anxious, but I know they’re working hard to make things happen,” said Santos, who is bringing up two children with Volpe.

The delay underscores the difficulty of securing approval for gay marriage, even in a state with strong Democratic majorities in the legislature and a Democratic governor who supports it.