Since the short-lived HealthCare.gov website meltdown last fall, conventional wisdom has held that Obamacare is a political loser for Democrats -- that whenever the Affordable Care Act comes up, Democrats running for office should quickly change the subject.

That conventional wisdom is wrong. Not only is going on offense on health care good politics; it's a moral necessity. And Medicaid is the place to start.

In two dozen states, Republican governors and state legislators are refusing to allow their constituents to take advantage of the expanded access to Medicaid that's part of the Affordable Care Act. As a result, more than 5 million Americans are being denied health care -- many are getting sick and some will die.

That's appalling. For no good reason other than pure ideology -- and that it underscores just how stridently they oppose President Obama -- these Republican governors and legislators have set up a blockade between millions of their their constituents and the doctor's office.

It's not like there's a fiscal reason to keep people from getting health care through Medicaid. This program is a huge bargain for states. The federal government is committed to paying 90 percent or more of the cost, forever. State budgets would see significant savings from things like reduced emergency room visits. Ending the Medicaid blockade is the fiscally conservative thing to do.

And people in every state already pay taxes to fund Medicaid, so what these Republican governors and legislators are doing is essentially taxing their own citizens and then sending the money away to pay for coverage for people in other states. Call them "tax and send" Republicans.

Given all this, it's not surprising that the Republican Medicaid blockade is bad politics. New surveys this week conducted for MoveOn.org Political Action by Public Policy Polling show that in state after state, including many red states like Kansas and Kentucky, far more people support expanding access to Medicaid than oppose it. And voters say they're less likely to vote for candidates who are on the wrong side of the issue.

So why are so many Democrats still playing defense on the health care, with weak-kneed "keep and fix" rhetoric that implies the Affordable Care Act is broken? The Affordable Care Act is not broken. It is serving tens of millions of Americans, expanding coverage, improving care, and keeping costs low. Last week's great news that more than 7 million Americans signed up by the enrollment deadline has caused media outlets to hit the reset button on their negative coverage. The dishonest Koch brothers can't even find a single real horror story to put into their health care attack ads -- every ad their front group has aired that features a "true story" has been debunked. Sure, we can all agree that there are ways to strengthen and improve the law, but that doesn't mean it needs to be "fixed."

Let's show some spine and go on offense. The thing that needs fixing is the fact that Republicans are intentionally blocking five million people from getting health care. They're the ones who have the explaining to do. We should be leaning into this fight with everything we've got.

And that's exactly what MoveOn members have been doing. A month ago, we launched a major national campaign to hold Republicans accountable for blockading Medicaid in every state where they're doing so. Since then, MoveOn members have done a ton of organizing, held rallies and demonstrations, run radio, TV, and online ads, and, in nine states, put up billboards.

One billboard, criticizing Louisiana Gov. Bobby Jindal for denying Medicaid to 242,000 Louisianians, so got deep under Republicans' skin that the state's lieutenant governor actually sued MoveOn to try to force us to take it down. That didn't go so well for the lieutenant governor.

Meanwhile Gov. Jindal was so thrown off by the criticism that his best comeback was that because MoveOn supports Medicaid, it must mean we hate people with disabilities. Really. He actually penned an op-ed asking, "What does MoveOn have against people with disabilities?" The fact that that's the best argument Gov. Jindal has to defend his stance on Medicaid exposes the profound weakness of his and other Republicans' position.

Some Republican governors, like John Kasich in Ohio and Jan Brewer in Arizona, have been smart enough to get out ahead of the issue and allow citizens in their states to access to Medicaid. But most Republican governors haven't, yet.

While Republicans in Congress have acted like nihilists, with over 40 Obamacare repeal votes in the House, Republican governors and legislators have been far more nefarious. It's Republican governors and legislators who have been actively denying people health care. And real people have paid the tragic price -- like 32-year-old Florida mom Charlene Dill, who died after she wasn't able to afford care for a treatable heart condition because she fell into Florida's Medicaid gap. Yet Republicans have the gall to accuse Democrats of setting up death panels?

It's time for the outrageous Republican Medicaid blockade to end. Let's build the political pressure that's needed to persuade Republican governors and legislators to change their minds. And if they don't, let's make sure their constituents understand what's happening, so that there can be accountability at the ballot box, and so five million Americans can get the health care they need.