A mock oil pipeline is carried during a Keystone XL tar sands oil pipeline demonstration near the White House in Washington, D.C., on Nov. 6, 2011.  (Andrew Harrer/Bloomberg)

President Obama is fond of telling Congress that it should pass things with the overwhelming support of the American people, including (among other things) comprehensive immigration reform, increasing the minimum wage, and increasing gun background checks.

And yet, Obama could soon be in a position of vetoing something with a similar amount of support: the Keystone XL pipeline.

Poll after poll has shown support for Keystone is somewhere between very strong and overwhelming. A Pew Research Center survey this month showed support for the project at nearly two-to-one, 59 percent to 31 percent. And that was about the lowest level of support we've seen to date. Support has registered as high as two-thirds of Americans.

And as another recent Pew poll showed, it's not just Republicans and independents driving support for the project. In fact, basically the only group that opposes it is the most liberal of Democrats.

According to Pew's breakdown from June, three of the four Democratic-leaning groups -- including religious Democrats, young Democrats and the most moderate Democratic leaners -- all supported the project two-to-one.

Keystone2

Which is a long way of saying that Obama would likely have very few supporters were he to wield his veto pen, as the White House suggests he will following votes by the House and Senate -- which by all indications will approve the bill.

The White House, if it does veto the bill, will apparently argue that it can't approve it before the lengthy State Department review of the project's environmental impact is complete -- along with a Supreme Court case in Nebraska concerning a key part of the pipeline's route. That's fine, but it still remains that a strong majority of Americans are pretty keen on getting the pipeline done.

The question from there is how strongly Americans feel. On issues like the raising the minimum wage and increasing background checks, support is overwhelming but soft, and the opposition is often louder than the proponents, despite being a small minority. Which means there is little outcry when Congress doesn't comply with public opinion.

On Keystone, a March Washington Post-ABC News poll showed 62 percent of American believed "strongly" that the project would create a significant number of jobs -- though we would note that the vast majority of the jobs would be temporary -- while just 28 percent "strongly" believed that it would pose significant risks to the environment.

The first thing to know about the Keystone pipeline? It already exists. Here's a breakdown of the pipeline's various parts. (Gillian Brockell, Jhaan Elker and Kate M. Tobey/The Washington Post)

Obama has only vetoed two pieces of legislation so far in his presidency. Such is the benefit of controlling one of chambers of Congress (the Senate) for all six years.

Republicans hope having control of both chambers will mean, rather than the Senate effectively vetoing bills from the GOP-controlled House by not voting on them, they will be able to put the decision in Obama's hands, at which point public pressure on something like Keystone could be brought to bear.

And it looks like Obama will quickly be forced into making one of his toughest veto decisions -- at least when it comes to the court of public opinion.