Because I've had to answer these questions over and over again, let's just get it all out of the way now.
First off: no, the Democratic state senators had no other recourse but to flee the state if they wanted any chance of altering the budget/collective-bargaining bill to suit their needs. No compromise has been offered by Scott Walker; all but one of the Republican state senators have marched in lockstep from the outset (Dick Schultz has been the exception, but three Republicans would need to flip, not just him.)
Were the Democrats to return, they could simply vote no. But they would get nothing. Absolutely nothing. Considering the antics of the State Assembly on this same issue, they might not even get that vote. Any protestation to the bill they made on the floor would pretty much go in one ear and out the other. They might as well recite the lyrics to John Jacob Jingleheimer Schmidt for all the good it would do.
There is another aspect to the Democrats having run. Without them having run, had the vote just gone along as scheduled, how aware would you be of the issue in the first place? For a significant number of you, it likely would have flown under your radar, and been dismissed fairly quickly, as there was no time for it to stick in your mind. As it is, though, you know full well where everybody stands. You know what Walker wants to do, you know what the Democrats want to do, and you know neither of them are budging. That doesn't happen if the Democrats stay in Madison.
As for 'doing their job'... their job is to protect the interests of their constituents, using whatever parliamentary maneuvers are at their disposal, just like any other elected official. If that can only be done by hopping the state line and preventing a vote that they believe heavily damages the interests of their constituents from taking place, their job is to prevent that vote. For them to return to Madison and allow the vote they believe damages the interests of their constituents, that would be them not doing their job.
For those who say 'I agree with the Democrats, but did they really have to go to Illinois?', the answer is yes. As it stands now, that's all there is to it. With the fundamental lack of trust by either side for those across the aisle, and the utter impossibility of compromise at our current state, the fate of collective bargaining currently rests on how long the Democrats remain in Illinois.
So what happens if nobody folds? That's the second thing I've heard over and over.
Imagine an MMA fight. Right now, both sides are employing a number of submission holds, trying to get the other side to tap out. But tapping out is ultimately the decision of the fighter in the hold. No matter how strong the hold, even if the opponent's arm is snapped clean off his body, if he doesn't tap out, the fight continues. (We are assuming no referee around to stop the fight.) As of right now, submission holds are all either side has to work with. Nobody yet has a knockout punch to throw, something that would not give the other side the option of continuing to fight. For all the talk about the pressure building and doubling down and whatnot, as long as the Republicans opt not to compromise, and as long as the Democrats remain in Illinois, all they can do is apply submission hold after submission hold. And with the fight being as existentially hostile to compromise as it is, submission holds do not appear sufficient to end the fight. The two sides appear fundamentally incapable of working with each other. It would take a knockout blow, something that changes the personnel involved.
Knockout punches are available, in the form of recall elections. But those take time. Both sides have started gathering signatures for recall elections on the eight state senators per side currently eligible for recall (you have to be in office for one year). It takes 60 days to gather those signatures, though- both sides have started the clock, but neither is that far along. The signatures must be turned in no later than 5 PM on Day 60. Chris Bowers outlines the process for Daily Kos. Republicans in the audience, the procedure is the same for you; just alter the names. The signatures gathered must be 25% of those votes cast in the constituency in the last gubernatorial election. As it stands, that works out to around 15-20,000 signatures per senator at risk.
If the signatures are gathered, a six-week certification process begins, followed by a 6-10 week election period. 6 weeks if there is no primary, 10 weeks if there is; the primary, obviously, takes up the extra four weeks.
Who would go first? It depends on several factors- are there any primaries, when are the signatures handed in and certified, etc. However, the Republicans started the clock first, though, so all things being equal, it'd be them by a couple days. They only need to knock out one Democrat to get their quorum. However, a group from Utah started the clock, and little if any time was taken to gauge where the signatures they need might be. That may hinder their efforts.
If they fail to knock out any Democrats, the Dems (who did go out looking to see where the signatures are; I touched on this in my Madison report) then get their shot a few days later. Again, all things being equal. They need to knock out three Republicans in order to retake the majority, splitting the state legislature and effectively killing the budget as proposed. Knocking out two might bring swingman Dale Schultz into play, who is not currently eligible for recall.
Added up, from giddy-up to whoa, should nobody tap out, it could be a six-month wait to see anyone knocked out.
That's one long submission hold.