If the latest polls and predictions are to be believed, the real question on Nov. 4 is not whether Republicans will win the Senate, but by how much.

Democrats really do have Obama to blame for this. With the president's approval rating sputtering after the administration's bungling of HealthCare.gov, ISIS, and Ebola, it's no wonder GOP voters are more fired up and ready to go than the Dems. But President Obama will ruin his party's presidential prospects in 2016 too if he allows the deflating midterm results to spook him into scaling back or abandoning his long-promised executive action on immigration.

He'll be under real pressure to give up. RNC Chair Reince Priebus has been promising the GOP faithful that if his party takes the Senate, it will do everything in its power — "defunding, going to court, injunction…you name it" — to stop Obama from declaring "executive amnesty."

This is a poetic mischaracterization of what the administration has proposed given that executive action can't actually offer amnesty — meaning a path to citizenship or even permanent legalization — but instead, only temporary stay from deportation and a work permit. Be that as it may, Obama must not back down.

Some liberal commentators worry that the president will do just that. Vox's Matthew Yglesias argues that pushing a controversial initiative after losing an election would leave the administration vulnerable to accusations that it is trying to overturn an "adverse result." Furthermore, notes The New Republic's Brian Beutler, Republicans will "place 'executive amnesty' at the center of proximate fights over funding the government and increasing the debt limit" — meaning they will argue that Obama can't be trusted with more power or money.

These worries are not unjustified, especially given that the administration has repeatedly prioritized other issues — ObamaCare, for example — over immigration. But doing so again wouldn't be smart — from a political or policy standpoint.

Many Latinos are disgusted by Obama's midterm switcheroo on executive action — he deferred action till after Nov. 4 for nakedly political reasons. But cynical as his decision may have been, it did make a certain amount of political sense. Of the 10 toss-ups that are in play next week, only one — Colorado — has a significant Latino presence. Deferring action will certainly depress their turnout next week (although by how much is debatable since Latinos don't show up in huge numbers for the midterms anyway). But forging ahead would have mobilized far more whites in the other nine states, making next week even more of a rout of Democrats, especially since the gap is no more than a few percentage points in most of these races.

But in the 2016 presidential election, this dynamic will fundamentally change: Latinos will be a crucial factor in far more swing states. Indeed, the president himself admitted to The Des Moines Register before the last presidential election that the one big reason he would capture a second term is because the GOP had so thoroughly alienated Latinos, the fastest-growing demographic group. And what was true then is going to be even truer next time.

Latinos made up 11 percent of the eligible voting population in 2012, and that number will be even higher by 2016. It will rise by 2 percentage points in critical presidential swing states, including Florida (where their share of the electorate will hit 19 percent), Colorado (16 percent), and Nevada (18 percent) — as well as New Mexico (42 percent), Texas (29 percent), and Arizona (22 percent).

That ought to give Democrats an automatic advantage except for this fact: Just because Latinos are eligible to vote doesn't mean that they will. Only 50 percent of them turn out compared with 66 percent of whites; that's one reason why Texas is still so reliably red. Latinos' 2012 turnout rate was higher because Obama had vowed to push immigration reform through Congress on a priority basis in his second term.

Latinos are perfectly aware that Obama's failure to deliver was in no small part due to the obstructionism of a small subset of loudmouthed House Republicans. Latinos might have forgiven him for that — except that he has removed more undocumented immigrants from the United States than even President Bush, earning the soubriquet of deporter-in-chief. Worse, he has been downright heartless in how he's dealt with unaccompanied Latin American minors seeking asylum, pressing to deport them without even the hearing required under a Bush-era law against human trafficking.

So the only way to inspire Latinos to make the schlep to the voting booth and pull the lever for Democrats in 2016 is to make good on Obama's promise and offer their unauthorized loved ones deportation relief. But that isn't the only political advantage of pushing executive action.

Everyone (even Real Clear Politics' election analyst Sean Trende, who authored a compelling series called the "missing white voters," noting that Republicans can become more competitive by concentrating on white voters) acknowledges that Republicans will have to do better than the 27 percent Latino vote that Mitt Romney got in order to win presidential elections. At the very minimum, that will require them to back off from the kind of harsh anti-immigrant rhetoric that Romney and other Republican presidential hopefuls deployed during the last primary.

But they can't do so while raising a big stink over executive action. Making that the central issue in budget fights will rally Latinos not just to vote for Democrats — but against Republicans. It would cement Republicans' reputation as an anti-Latino, anti-immigrant party, hurting its prospects in the long term when whites do become a mere plurality. What's more, many Republican governors in Latino-dense states, such as Rick Scott in Florida, are making an all-out drive to attract Latinos. Congressional Republicans' harsh talk will intensify the civil war in the party, all of which will redound to the benefit of Democrats.

If Republicans were smart, they'd counter President Obama's executive action with their own immigration initiative to steal some of his thunder and minimize the political damage to themselves.

Thus both from the standpoint of policy and politics, it would be wise of the president to dust himself off after next week's likely defeat, stand his ground, and tell Priebus: "Bring it on, buddy."