The Democratic National Convention has been showcasing a number of “defections” from the Republican Party to back Joe Biden’s bid for the White House. Some, like Colin Powell, hadn’t voted Republican in a while so it’s hard to call them defections. But one look at other defections shows why grassroots conservatives took a chance on a billionaire New Yorker and former Democrat named Donald Trump.

As we’ve acknowledged before, Trump’s style and presidency have been anything but smooth sailing. But, like chemotherapy, he’s been an essential treatment for some very serious problems.

One of those problems was a Republican establishment that had difficulty winning national elections and standing up to the slings and arrows of the Democrats and their Leftmedia brethren. And even when Republicans won elections, they rarely seemed to advance conservative issues.

Let’s take a look at the Left’s latest media darling, John Kasich, the former Republican congressman, Ohio governor, and failed presidential candidate who was featured on the opening night of the Democrat convention. On one core issue for conservatives — national security — Kasich is responsible for helping make our position with China far weaker than it had to be. In the mid-1990s, Bill Clinton’s administration wanted to halt B-2 bomber production at 20. Many on the Republican side wanted to see at least 40 of these advanced bombers built — and that number probably should have been even higher. Kasich, though, came through for Clinton by teaming up with hard-left Congressman Ron Dellums to support this cut, cap our B-2 production, and weaken our national security. These days, with our bomber force in a pinch and an aggressive China and a meddlesome Russia, wouldn’t America be safer with a few more B-2s on hand?

We won’t even bother to address Kasich’s notable squishiness on the Second Amendment.

John McCain, the deceased former Republican senator, Armed Services Committee chair, and failed presidential candidate, also fought to cancel a number of advanced weapons systems. For example, he helped Barack Obama stop the F-22 Raptor’s production at 187 airframes, when we needed at least 200 more.

In the best case, as with the Air Force’s KC-46 tanker, which is now having some bugs worked out, badly needed new systems have been delayed. But in the worst case, as with the Expeditionary Fighting Vehicle, the Seawolf-class submarine, and other planes and ships, far too many vital systems were halted too soon.

When it comes to ensuring that our troops are properly equipped, we’re not surprised to see Democrats oppose the necessary funding. But when Republicans start slashing away at needed weapons systems, we have a right to ask why.

This, of course, is just one of many failures of the establishment to stand up for the interests of grassroots Patriots. McCain’s infamous and decisive “thumbs down” on the repeal of ObamaCare was another. Even now, establishment types are wringing their hands over Trump’s call to boycott Goodyear due to its double standards about acceptable political messaging. Where were these people when Goya’s CEO was attacked and his company boycotted for his sin of having praised the president?

These failures, and the GOP’s unilateral political disarmament, led to an inevitable loss of trust among Republican voters and to the rise of Donald J. Trump.

And so, despite having trotted out these failed establishment figures in support of Joe Biden, the Democrats are unlikely to convince Republican voters that they made a mistake by giving Trump a shot.

Instead, they’ll merely convince voters that they should have dumped the establishment sooner.