SPRINGFIELD — It’s a start. An important start.

As much as Thursday’s Illinois House passage of a state budget over Gov. Bruce Rauner’s vetoes may seem like crossing the finish line of a marathon, it’s not.

There is a long, long way to go to put Illinois back on track.

I’ll agree with that much of what I heard from the Republicans who carried Rauner’s banner (water) into Thursday’s floor debate, although my gratitude goes to the 15, now down to 10, who split with them to join Democrats and pass a budget.

I don’t know if Rep. Steven Andersson, the Geneva Republican who helped forge the compromise, has any interest in higher office, but I’m always looking for a legitimate way to split my ballot.

OPINION

Let’s hope Andersson and his Democratic counterparts, Rep. Greg Harris and Rep. Will Davis, join with their Senate colleagues and turn their attention immediately to the thornier issues that remain to be addressed now that the budget is finally out of the way.

One seems difficult, but doable. That’s figuring out a way to pare down the state’s $15 billion backlog of unpaid bills. Note: It takes money to pay bills.

Unfortunately, I’m not sure anybody has shown a workable plan for the larger problem of how to deal with the state’s massive unfunded pension liability. A budget funded with an income tax hike allows the state to make the necessary payments for now, but that’s still a looming train wreck that can’t be ignored.

And before we deal with either of those matters, we’re going to need bipartisan agreement on school funding, which may require another Rauner veto override just to get schools open next month.

That may end up tied to a property tax freeze with a lot of loopholes to limit the damage to local governments.

SCHOOLS: Long-awaited budget vote won’t yet solve school funding problems
CULLERTON: Budget is ‘win’ for Rauner — if he’d just admit it
BROWN: Rauner on high horse, where he’s most comfortable
LONE VOTE: GOP senator says ‘my district told me to’ back budget
THE VOTE: Here’s how the Illinois House voted for tax bill override
TAXPAYERS: Some resigned, some upset — and some leaving

I’ve been covering the Capitol many years, so it’s significant that I experienced a couple of personal firsts Thursday.

It was my first opportunity to be involved in a security lockdown, the chance to “shelter in place” for two hours made easier by the early indications there was no real threat. A woman with a “white powdery substance” sounds a lot less scary than a man with a gun.

But it resulted in an odd two-hour delay before the main event, which only took one hour start to finish. Nearly all of that was taken up by Republican speechifying on the horrors of an income tax increase, which many of them know was unavoidable.

My favorite comment may have been from Rep. John Cabello (R-Machesney Park) who, just before voting to uphold Rauner’s veto and continue the impasse madness, asked plaintively: “How come we couldn’t come to this resolution a year ago?”

I can answer that. Because it took that long for enough of Cabello’s fellow Republicans to come to the realization that their governor had overplayed his hand and was making a bad situation worse in his effort to teach Democrats who is the boss.

Which leads to my other first: It was the first time I saw a major tax increase enacted over a governor’s veto, a stunning repudiation of Rauner’s belligerent tactics.

There were indications Thursday that the state Republican Party might seek revenge against the GOP defectors who backed “Madigan’s 32 percent income tax increase.” That’s a tricky business.

(As an aside, may I note that no matter how many times Rauner calls it “Madigan’s tax increase” — or how many others mimic him — it doesn’t make it so.)

The 15 House Republicans who voted for the tax increase, only 10 of whom voted for the override, were already subject to plenty of abuse in the past few days without any official party sanction.

All of them still have a year-and-a-half remaining in their terms, and it won’t help Rauner if they’re so alienated that they team with Democrats on more compromises and overrides.

Now that they’ve had the experience, they might consider sheltering in place.