Forget Pelosi for a moment and contemplate the truly horrible omnibus bill which manages to have amnesty for illegal aliens baked in along with making even the limited fencing unbuildable, as Daniel Horowitz points out.
Section 232(a) of this bill states that “prior to use of any funds made available by this Act for the construction of physical barriers” the Department of Homeland Security “shall confer and seek to reach mutual agreement regarding the design and alignment of physical barriers within that city.” With whom must the feds consult? “The local elected officials.” Now you can understand the brilliance of limiting the wall to the Rio Grande Valley. These are the most liberal counties on the border (thanks to demographics of open borders itself!), and there is practically no local official who supports the wall in these counties.
Are Republicans stupid? Nah.
It's the same "stupidity" which led them to endorse the Iran Deal while pretending to oppose it. Let's pretend that these folks had expended a fraction of the passion they feel for protecting Iran's Houthi terrorists from Saudi Arabia on building a wall.
It would be very different.
A nice big chunk of the Republican establishment supports illegal alien amnesty and opposes anything that interferes with it. So it was never going to happen. Not even if Republicans made up 99% of the House and the Senate.
An emergency declaration is a potential pathway. Though not a really necessary one. And with the Trump admin's insistence on deferring to Federal courts, every Obama and Clinton judge will be busy finding reason why the wall interferes with X, Y or Z.
And that's not how emergencies get handled. But it's still a likelier path than waiting for the Senate to do the right thing.
The omnibus bill meanwhile is, predictably, utterly terrible and if signed will inflict decades of damage on our immigration system.