Yesterday, before Republicans won the special election in Florida’s 13th district, Democrats were facing a daunting challenge for 2014: Defending Senate seats in seven states carried by Mitt Romney, amid a sluggish recovery, widespread economic pessimism and low Obama approval ratings.

Today, after Republicans won the special election in Florida’s 13th district, Democrats are facing a daunting challenge for 2014: Defending Senate seats in seven states carried by Mitt Romney, amid a sluggish recovery, widespread economic pessimism and low Obama approval ratings.

Yesterday’s GOP victory is being widely portrayed as a sign that Republicans are already succeeding at broadening the Senate map for 2014 into territory that should be safe for Democrats, with Obamacare being the reason why.  But does FL-13 — certainly a tough loss for Dems — tell us all that much that we don’t already know?

To be sure, if Republicans can broaden the map to seriously put states like Michigan and Colorado in play, they’ll likely win the Senate, because Dems would be on defense in too many states. Dems will have to aggressively defend both no matter what, but there’s a distinction to be made between Dems waging campaigns in them and winning by mid- to high-single digits on the one hand and them being seriously contested on the other.  If it’s looking like the former, it means Republicans aren’t seriously broadening the map – and control will be decided in the red state battlegrounds, where Obama is hideously unpopular, which is the fundamental structural problem we knew Dems would face. But if it shapes up as the latter, that means Republicans really are broadening the map. This unknown is central to the battle for Senate control.

What does FL-13 really tell us about this? I argued back when everyone said Alex Sink would win, and again more recently, that reading too much into this one special election is a mistake. Sure, for Dems this is a demoralizing loss and a reminder that the current environment is very bad. But there are too many variables in play to say whether this means Dems will be in serious trouble in states like Michigan and Colorado many months from now. Maybe they will be, but we just don’t know yet. Does yesterday’s loss prove that Dem “keep and fix” message is also fatally flawed in statewide races? Anything is possible, but it’s unclear what alternatives Dems have, and again, we just don’t know yet.

That said, perhaps yesterday’s loss was just the thing to jolt Dems into taking the structural disadvantages they face more seriously. Top Dems are already worried their donors aren’t kicking in to counter the massive ad blitz Americans for Prosperity has unleashed in red states. Maybe yesterday’s loss will cause that Dem money to flow and force Dem operatives to think more effectively about what it will take to help embattled red-state incumbents hang on. After all, the GOP victory will only deepen Republican certainty that their anti-Obamacare message is a sure winner, meaning hundreds and hundreds of millions of anti-Obamacare ads over the next eight months, with the escalation to begin any day now.

* OBAMA’S LOW APPROVAL A HEADWIND FOR DEMS: The new NBC/WSJ poll finds that Obama’s approval is at a low point of 41 percent, with 48 percent say they’re less likely to vote for a candidate who supports the Obama administration, versus 26 percent who are more likely. Meanwhile, Republicans hold a slight lead in the generic ballot matchup, 44-43, and as NBC observes: “Republicans have traditionally fared well in elections when they’ve held a slight lead on this question.”

Once again: Republicans will win a lot of seats this fall. The question is whether Dems can limit their losses, particularly to the degree they need to in the Senate.

* PUBLIC SPLIT ON OBAMACARE REPEAL: The new NBC/WSJ poll also finds, as usual, that Obamacare polls badly, with 35 percent saying it’s a good idea, and 49 percent a bad idea. And:

Forty-eight percent of voters say they’re more likely to vote for a Democrat who supports fixing and keeping the health-care law, versus 47 percent who are more likely to back a Republican who favors keeping and eliminating the law.

This is in line with suggestions by Dem pollster Stan Greenberg and others that Obamacare is ultimately more of a polarizing issue than a wedge against Dems.

* A NATIONALIZED ELECTION? Some folks are arguing that yesterday’s result proves the election is being nationalized to the GOP’s benefit. But the new NBC/WSJ poll finds that 44 percent say their Congressperson’s position on national issues is more important to them, while 51 percent cite their performance in their district. What’s more, 33 percent say their vote will be a signal of opposition to Obama, while 24 percent say it will be a signal of support and 41 percent say it won’t be a signal either way.

* RENEWING THE PUSH ON MINIMUM WAGE: The centrist group Third Way is out with a new memo pushing back hard on the Congressional Budget Office’s recent finding that a minimum wage hike could reduce employment by 500,000 jobs. The memo notes we already have a real world experiment:

Economists Andrajit Dube, William T. Lester, and Michael Reich looked at hundreds of adjacent counties with different minimum wage laws over the course of more than a decade to see whether counties with higher mandated wages lost or gained jobs. The authors found that modest minimum wage increases did not result in job losses — not in retail, not in accommodation, not in food services….The most comprehensive case study — in terms of time, geography, and industry — asserts that a modest increase in the minimum wage has no impact on job creation or destruction. It’s time to raise the minimum wage.

Yesterday’s loss in FL-13 will probably lead Dems to redouble the push on this front.

* MEDICAID EXPANSION FIGHT LOOMS IN LOUISIANA: This is interesting: Americans for Prosperity is having trouble getting GOP lawmakers in Louisiana to sign a pledge opposing the Medicaid expansion, which is being debated for the state this spring. Remember, Dem Mary Landrieu — who is criticizing Obamacare — is also aggressively advocating for the Medicaid expansion, and this will become a major issue in the Senate race there, another sign the politics of Obamacare could prove more complex than Republicans think.

* IN MICHIGAN, OBAMACARE IS COMPLICATED: In Michigan, another state AFP is blitzing with anti-Obamacare ads, the GOP Senate candidate there is now voicing support for not just the Medicaid expansion, but other elements of the health law as well. It’s another sign the GOP repeal stance may prove increasingly untenable, despite broad conclusions being drawn from a single special election in Florida.

* AND OBAMA PLANS MOVE ON OVERTIME PAY: The New York Times scoops that Obama will move to use executive authority to force employers to pay workers more overtime pay to millions of workers:

On Thursday, the president will direct the Labor Department to revamp its regulations to require overtime pay for several million additional fast-food managers, loan officers, computer technicians and others whom many businesses currently classify as “executive or professional” employees to avoid paying them overtime, according to White House officials briefed on the announcement.

This is a suggestion Obama may now be willing to use executive actions in ways that will antagonize the business community, if so doing is required to get around Congressional GOP opposition to all Dem proposals to boost the recovery and economic mobility.

What else?

Greg Sargent writes The Plum Line blog, a reported opinion blog with a liberal slant -- what you might call “opinionated reporting” from the left.