I want a wall – a big, beautiful wall that cannot be climbed.  I have heard objections, and I don't care.  A wall is "due diligence" in border security, not an infallible guarantee.  Home security starts with locked doors and windows, and border security starts with a wall.

As for the objections:

1. A wall is not immoral. Speaker Pelosi probably hasn't had time to read Revelation lately, but verse 21:12 describes the New Jerusalem as having "a great and high wall with twelve gates."  This is the city of God, His dwelling place, filled with His glory, and it has a wall.  Neither God nor anyone in His city is concerned about crime, perhaps because (v. 15) "outside are dogs and sorcerers and sexually immoral and murderers and idolaters, and whoever loves and practices a lie."  (Insert favorite reference to politician or journalist here.)  We lack divine control of borders, but wanting a wall isn't immoral and cannot be if God Himself allows them.  I don't expect that argument to convince atheists, but Nancy Pelosi is a self-identified Catholic.
2. A wall is not expensive.  Last year's federal budget was on the order of four trillion dollars.  Think of it as four followed by twelve zeroes.  The coming year's budget will likely be higher, but even using the same figure, how much is President Trump asking for to build part of a wall?  Five billion – a five followed by nine zeroes.  According to my calculator, that is 0.125% of the budget.  For comparison, if you make $10 an hour and work full-time (168 hours per month) for an annual pre-tax salary of $20,160, it would be $25.20 for the year – "crumbs," Madam Speaker, by almost anyone's standards.
3. A wall is effective.  It depends on the wall itself, of course.  Yes, some people will have ladders or dig tunnels, and we will neutralize those items as we find them.  Yes, some people will get in illegally to our country all the same.  Yes, many people will come in legally and then overstay their visas, and the wall won't stop them because they'll have come through a port of entry.  The wall will make unauthorized entry more difficult and provide us the opportunity to screen out the undesirables – e.g., the known criminals.  If we adopt a philosophy that only that which is 100% effective may be funded, there goes most of the federal budget.  The FBI and CIA don't catch all the criminals.  Social Security doesn't always have accurate records, so sometimes it sends checks to dead people and fails to send checks to live ones.  The USPS sometimes loses mail.  And so on.
4. A wall is symbolic of closed borders.  Sure, some people want open borders, but if we have them and Mexico doesn't, then the border isn't really open – just unguarded on our side.  A wall implies strength and the resolve to defend our borders.  It's a warning that transcends language barriers.

I have nothing against electronic security, but exactly how secure is an electronic barrier?  Sure, you can have sensors linked to alarms that announce incursions, but invaders aren't going to react by running south.  They'll run north into U.S. jurisdiction and get to the front of the asylum line because they're already here.  And just maybe they won't be apprehended at all.  It's worth the risk because, to them, the U.S. is obviously not serious about border security.  So what exactly is an electronic border security system going to do to stop them from crossing?

Nothing.  That's why the Democrats are for it.