The Republicans are trying to blame the government shutdown on the insistence by Democrats that Congress finally take action to protect the so-called Dreamers.

“This vote should be a no-brainer,” as Senate Majority Leader Mitch McConnell put it, “and it would be, except the Democratic leader has convinced his members to filibuster any funding bill that doesn’t include legislation they are demanding for people who came into the United States illegally.”

It’s not quite that simple: A number of Republican senators have joined in the filibuster as well. But overall, there’s certainly some truth to McConnell’s statement, and an awful lot of history to consider as well.

Let’s begin with the fact that helping the Dreamers out of their predicament is widely popular, and that support is longstanding.  In a CBS poll last week, 87 percent of Americans -- including 79 percent of Republicans -- said they supported a way to legalize those who were brought to this country illegally by their parents, who think of themselves as American and in most cases know no other country.

President Trump also says he wants to help the Dreamers ... someday. House Speaker Paul Ryan says he wants to help the Dreamers ... someday. His predecessor as speaker, John Boehner, promised over and over again to help the Dreamers ... someday. Yet someday never arrives.

U.S. Sen Dick Durbin of Illinois introduced his initial version of the DREAM Act way back in 2001, some 17 years ago, to try to help a young piano student from South Korea brought here illegally by her parents. A hearing on his bill was scheduled for September of that year -- Sept. 11, 2001, to be precise. Other priorities intervened.

Since then, various versions of the bill have passed either the House or Senate, only to die at Republican hands in the other chamber. In 2012, out of frustration with Congress, President Obama created the DACA program to provide the Dreamers with temporary protection against deportation. In 2013, the DREAM Act was part of a comprehensive, bipartisan immigration reform package that passed the Senate  with 68 votes, but the Republican House refused to allow a vote on it, knowing that with the support of Democrats and moderate Republicans, it would pass.

House Republicans then promised over and over again to introduce their own version of immigration reform, including help for the Dreamers, but never did. House Majority Leader Eric Cantor pushed his caucus hard for a vote, but in 2014 that attempt at leadership got him defeated in a Republican primary.

That was also the year that Boehner gave us this memorable outburst:

For 17 years, this legislation has been in limbo -- highly popular with voters, endorsed theoretically by Republican leaders but blocked repeatedly by those same leaders. From their point of view, the logic is pretty simple:

If Republicans allow a vote to legalize the Dreamers and give them a path to citizenship, they will anger and betray their far-right wing and be condemned for committing the mortal sin of amnesty.  Ryan might be deposed as speaker; others fear meeting the same fate as Cantor.

They also know that if they allow a rollcall vote, large numbers of the Republican caucus will go on record against the legislation, cementing their party’s reputation as racist, mean and cruel. Politically speaking, they see no upside to allowing a vote, and only pain if they do.

So yes, what we’re seeing now in Washington is an effort by Democrats to change that calculation, to force their Republican colleagues to finally, finally do the right thing, the correct thing, the humane thing. And if the Democrats are forcing a shutdown over helping the Dreamers -- which they are -- the opposite is also true: Republicans are forcing a shutdown over NOT helping the Dreamers.

Nothing changes until something changes -- we’ll see if the gamble pays off.