Editor's note: Ruben Navarrette Jr. is a CNN.com contributor, a nationally syndicated columnist and an NPR commentator.
San Diego, California (CNN) -- What if, as Americans, everything we thought we knew about the politics of border security were wrong?
Notice, I said "the politics" of border security. That means the way both political parties use and manipulate for political benefit what should be top priority: securing our nation's borders.
I mean "borders." Plural. Not just the southern one that separates our country from dark-skinned people whom many Americans consider inferior and dangerous.
Given what we hear in the public debate, we assume that Republicans are tough on border security, especially to combat illegal immigration, and that Democrats are soft.
But in politics, you have to ignore what people say and watch what they do. And, looking at what politicians do, it seems we have it backward. Republicans are the soft ones, and Democrats are trying to be tougher.
Neither party is acting out of a noble adherence to principle or what it thinks is best for the country. It's all about what's good for the party politically. That's interesting because, in these new roles, the politicos are going against elements of their base. They're gambling the base doesn't notice and they're able to bring in new voters or sew up political contributions.
No other conclusions can be drawn from the budget battle in Washington and the negative impact it will have on funding for security along the border.
First, the good news: Republicans managed to cut $4 billion in spending from last year in a stop-gap measure. But the bad news is they are proposing damaging cuts to border control and customs enforcement budgets that translate into losing hundreds of border agents and nearly $300 million worth of high-tech surveillance equipment.
That's a retreat from a $600 million emergency border security bill passed by Congress last August that, among other things, allowed for 1,000 new border patrol agents.
Aren't these the same Republicans who like to stoke the fires of the immigration debate by blasting the Obama administration, and the Democratic Party, as ineffective at guarding the border and who pitch themselves as the only ones concerned with securing it?
So much for truth in advertising.
Why would Republicans undermine what they claim to be their priorities? Maybe it's that their real priority is keeping big business happy, and the best way to do that is by providing a fluid border and a steady stream of cheap and dependable labor.
But that's only half the story. Who do you suppose is pushing in the other direction by fighting the Republicans and defending the border? The Democrats.
Three Democratic senators -- Jeff Bingaman of New Mexico, Charles Schumer of New York, and Jon Tester of Montana -- recently complained about the Republican budget's cuts in border security and wrote a letter to House Republican leaders, calling the changes -- 870 fewer border agents, for one -- "dangerous" and "irresponsible."
This is, let's remember, the same Democratic Party that normally disparages and dismisses the GOP immigration strategy of "enforcement only" and, at least rhetorically, supports a more comprehensive approach that legalizes the undocumented. That's what Democrats want their liberal base -- especially Latinos -- to believe.
But in truth, Democrats are too scared and too disinterested to propose a workable comprehensive immigration reform plan, or to even bring up the issue in any meaningful way.
Schumer has an immigration bill that doesn't have a prayer of passing because it deliberately leaves out language calling for guest workers that might have won some Republican votes. Besides, you'd never know the bill exists because Schumer has been so quiet and low-key about it.
The three Democrats resisting cuts to border control and customs better hope that this doesn't get back to Latino voters, who were under the assumption that Democrats were the grown-ups in the immigration debate. Latinos thought Democrats understood that even 20,000 border patrol agents, surveillance cameras on the border, and 20 foot-high walls are not enough to stop people who are desperate to feed their families from penetrating a barrier and seeking out a grueling and low-wage job that lets them accomplish this goal.
But what Democrats understand most clearly is that they can't continue to be re-elected by mainstream voters if they're perceived as "dovish" on border security. They also understand that their benefactors in organized labor want them to do a better job of keeping out illegal immigrants as a way of limiting competition for jobs.
That's it. That's what is happening in Congress on the issue of border security -- and why. And it's not good.
Americans like to talk about how we have a broken border. That's nothing. You want broken? Forget the border. Take a good look at our political system.
The opinions in this commentary are solely those of Ruben Navarrette Jr.