Missouri's House displayed unusual constitutional discipline during this summer's anti-crime special session.

House leaders obeyed a state constitutional provision which requires a bill be limited to a single subject.

It was a major change.

Increasingly, the legislature has created "bloated whale" bills by piling unrelated issues into a single bill to facilitate passage of separate ideas.

The special session began going down the same path.

The Senate jammed all the governor's anti-crime ideas into a single bill to cover witness protection, juvenile crimes, St. Louis city police residency, child endangerment and weapons transfer.

The whale bill appeared to be on the legislative fast-track.

But the House refused to consider the Senate's whale bill after Gov. Mike Parson's surprise expansion of his special session call to include giving the Republican state attorney general murder prosecution powers in St. Louis city if the Democratic circuit attorney did not file charges within 90 days.

House leaders decided to split the governor's proposals into separate bills. They issued a statement explaining their approach was "to protect the integrity of the lawmaking process, and to ensure these important issues are thoroughly vetted."

That approach did not seem to delay the process in the House, confirming my suspicion that a bloated whale bill took almost as much legislative time as single-topic bills would have required.

But the House approach fell apart in the Senate which attached the circuit attorney issue to a House-passed bill dealing just with allowing hearsay evidence if a criminal defendant attempted to intimidate a witness.

The witness provision had bipartisan support. Not a single House Democrat had voted against it.

But when the Senate added undercutting the St. Louis circuit attorney's authority to the witness-only bill, it had an unintended consequence.

Solid opposition from Democrats blocked approval of an emergency clause that would have put the law into effect immediately upon the governor's signature.

As a result, even if the governor got to sign the Senate version into law, prosecutors across the state will be denied for a few months a powerful tool in going after criminals.

That delay could have been longer.

In 2012, Missouri's Supreme Court rejected a whale bill noting the state Constitution prohibits changing a bill from "it's original purpose."

It's hard to understand how the Senate version defining the purpose as "relating to criminal procedure" is not a major change from the original subject of the House bill limited to just "the offense of tampering with a witness or victim."

Beyond that, in 1994, the court struck down a whale bill citing "logrolling" to combine unrelated provisions to get a majority vote.

This year, what were Senate Democrats to do? Vote for a witness protection measure they supported or against restricting powers of the Democratic city prosecutor?

The partisan elements of this issue were enormous by handing to a Republican white, male authority to take over murder cases from St. Louis city's elected female, black circuit attorney.

Earlier this year, Parson vetoed another whale bill. His veto letter charged the 37 provisions of the bill did not comply with the constitutional requirement of one topic for a bill.

His veto letter noted some of the provisions never had a public committee hearing.

That's just like the circuit attorney provision.

Because the governor's idea was so late in the process, it never got either a House or Senate committee hearing.

As a result, Circuit Attorney Gardner did not have an opportunity to defend herself in a public legislative hearing to Republican charges of inadequate pursuit of felony cases

The House rejected this approach on the last day of the special session, when it refused to even take the bill that included the governor's circuit attorney proposal.

It'll be interesting to see if the House displays the same constitutional discipline when the legislature returns next year.

Phill Brooks has been a Missouri statehouse reporter since 1970, making him dean of the statehouse press corps. He is the statehouse correspondent for KMOX Radio, director of MDN and an emeritus faculty member of the Missouri School of Journalism. He has covered every governor since the late Warren Hearnes.