The coyote is always most confident right before he falls off the cliff.

Which brings us to the Republican party. As wolfish Donald Trump moved closer to its presidential nomination this week by winning the Nevada caucuses, senators who argue Barack Obama won a three-year term vowed not even to consider the president’s nominee to replace late Supreme Court Justice Antonin Scalia. No hearings, no votes: They won’t even meet with the choice of the constitutional officer who still makes these appointments until Jan. 20, 2017.

From overreach on the court to the way Trump’s wins in South Carolina and Nevada played out, the week shows how Democrats can dismantle Trump this fall, while taking a run at the four-seat Senate pickup they need (all in states Obama carried) to control the chamber. Trump and the court fight are the same problem — the GOP’s botching of its need to expand its base, or hold down minority turnout, in presidential years.

Trump is revealing himself as just Trump — the content-free id who appeals to other content-free ids. “Winning, winning, winning,” he said in Nevada on Tuesday night. “There’s going to be so much winning.” Another round of tiger blood for Mr. Sheen, barkeep.

Exit polls’ most-notable finding about Trump is how poorly he does among those who make up their minds shortly before voting. He got 14% of late deciders in Iowa, 22% in New Hampshire and 16% in South Carolina, according to different surveys. In Nevada, he won by getting 59% of those who made up their minds by January, with Rubio winning late deciders. Trump’s act is there to see: People who like it, buy in; people who think first, mostly don’t.

With Trump carrying 58% unfavorable ratings in the RealClearPolitics polling average, and trailing Hillary Clinton by 3 points in RCP’s data, it’s not encouraging. She hasn’t even begun bombarding him with negative ads yet, and Democrats are warning that their strategy will be about tearing down Trump, if only because Clinton doesn’t excite anyone much. There’s lots to work with.

Trump repels a majority of voters even when he’s running against Ted Cruz, never captain of Team Affable-and-Popular himself. Yet John Kasich apparently isn’t built for GOP primaries, Ben Carson is a fringe candidate, and Marco Rubio is down to pinning hopes on March 15 primaries including his native Florida’s. Hence, Trump.

Trump thanks the 'poorly educated' after Nevada win

Against this backdrop, we have the “fight” over the court, in which the GOP Senate majority now says it will pretend not to notice when Obama nominates a replacement for Scalia. It’s a naked power play — voters understand that already.

Voters will soon understand what (and which groups) that power play protects — that’s the Democrats’ big job in picking a nominee, and selling him or her to Senate voters this fall. Democrats can make the Supreme Court fight about abortion, immigration, birth control, climate change, or other issues depending on polling and how Democrats use niche media to drive turnout.

Want to make sure black turnout doesn’t sag with Obama off the ballot? Nominate Circuit Court Judge Paul Watford, popular on shortlists anyway. Not only should Watford twisting in the wind scare Trump, who needs black turnout low, but red-meat appeals to minorities in Chicago, Philadelphia and Milwaukee should worry GOP Senate incumbents Mark Kirk (Illinois), Pennsylvania’s Pat Toomey and Ron Johnson (Wisconsin) too.

Make it California Attorney General Kamala Harris who gets shunned and ignored, and you get a black woman. More bad news for Toomey in Philly suburbs loaded with pro-abortion rights women, and problematic for New Hampshire Sen. Kelly Ayotte.

You can play this with a Latino such as Judge Adalberto Jordan, a Cuban-born former Florida prosecutor. Or Nevada Gov. Brian Sandoval, a Republican the administration is reportedly vetting. “The best candidate politically would probably be Hispanic,” SCOTUSblog’s Tom Goldstein writes. “Hispanic voters both (a) are more politically independent than black voters and therefore more in play in the election, and (b) historically vote in low numbers.”

When you have more than one minority in your party, it’s not Clarence Thomas or bust.

The GOP’s we-won’t-even-see-them strategy maxes out on disrespect for Obama’s nominee, born of insular cockiness the party never sheds, convinced they won in 2012 except among hoi polloi, who, remarkably, can vote. (They lost by 5 million votes.) Trump’s cockiness speaks (and speaks) for itself.

As Republicans blow off a nominee from a group — or groups — that feels disrespected/overlooked already, while nominating a would-be president who calls Mexicans rapists, they create their own problem.

One they can’t build a wall around.

Tim Mullaney writes about economics and politics for MarketWatch.