Democrats have a historic opportunity to win a landslide victory in the presidential election this year, as well as to make far-reaching gains in congressional elections and shape the Supreme Court for a generation.

Republicans are likely to nominate Donald Trump, a man who performs demented imitations of a disabled person, slanders Hispanic immigrants as rapists and murderers, retweets words of wisdom from Benito Mussolini, shares a mutual admiration society with Vladimir Putin, suggests it might be desirable for Saudi Arabia to obtain nuclear bombs, ridicules American POWs because he prefers troops who were never captured, suggests he would order American troops to commit war crimes of torture, repeatedly demeans women with terms like fat slob and bimbo, believes American workers are paid wages that are too high, and campaigns like Charlie Chaplin in “The Great Dictator.”

{mosads}Alternatively Republicans could nominate Ted Cruz, the favorite son of the GOP establishment with the Trump-given nickname “Lyin’ Ted,” who has called Senate Majority Leader Mitch McConnell a liar, is widely despised by most of his congressional colleagues, claims as his only noteworthy achievement in the Senate a government shutdown, and recently shared a sleazy dispute with Trump that was insulting to both of their wives.

Some time ago I wrote in The Hill that the GOP was in danger of becoming the party of “banana Republicans.” This is happening today, in real time. Many senior Republicans privately concede the presidential election represents a politically suicidal choice between their party losing with Cruz or dying with The Donald.

The banana Republicans in the Senate — part of a Congress disapproved of by more than 77 percent of Americans, according to RealClearPolitics — stand accused by Democrats of shirking their constitutional duties by refusing to consider or confirm the Supreme Court nomination of one of the nation’s most eminently respected jurists

President Obama’s favorable ratings have skyrocketed by contrast with the shabby performance of Republicans in the presidential campaign and Congress.

I agree with New York City Mayor Bill de Blasio, one of America’s leading progressive voices and a supporter of Hillary Clinton, who says Democrats are blessed with two extraordinary candidates who are both well-qualified to be president. My guess is that de Blasio could play an instrumental role in bringing the Sanders and Clinton forces together once the Democratic nomination is decided, along with longtime Kennedy confidant and former senator and Democratic National Committee Chairman Paul Kirk, who supports Bernie Sanders.

The most likely outcome of the primary battle is that Clinton emerges as the Democratic nominee. The most likely outcome of the general election is that she wins a landslide victory comparable to the 1964 victory of Lyndon B. Johnson over Barry Goldwater, which left Democrats with 68 Senate seats and 295 House seats. The congressional numbers in 2016 won’t be as large for Democrats as the result in 1964, but epic presidential landslides promise to bring dramatic gains in Congress for the winning party.

Compared to her GOP opponent, the former first lady, senator and secretary of State will look like a steady hand in a troubled world and a superbly experienced leader who will tower light-years above the banana republic shenanigans of the GOP presidential nominee and Congress.

Clinton will benefit from a huge surge of Democratic turnout from the large majority of women who intensely dislike Trump, Hispanic voters who will justifiably fear a knock on the door in the middle of the night ordered by a GOP president, gay voters alarmed by the anti-gay fever gripping GOP politics, millennial voters appalled by intolerant GOP policies and abusive tactics, and black voters disgusted by the prospect of a GOP president who questions President Obama’s Americanism and would destroy his legacy as both Trump and Cruz with a GOP Congress would do.

On recent shows for Newsmax TV, I playfully suggested to two conservative Republicans I like and respect that if Trump is nominated they might join Republicans for Hillary. They won’t, but others will  — and upon such events epic landslides are built.

Budowsky was an aide to former Sens. Lloyd Bentsen and Bill Alexander, then chief deputy majority whip of the House. He holds an LL.M. in international financial law from the London School of Economics. He can be read on The Hill’s Contributors blog and reached at brentbbi@webtv.net.