Christine O'Donnell's win in Delaware on Tuesday night is meaningful, significant, and important. Whether anyone in the mainstream media wishes to believe it to be true is irrelevant. Christine O'Donnell's win demonstrated that the establishment political party machine, and pundits pontifications were all wrong. It also demonstrates that 2010 is as truly a groundbreaking political year--a watershed even--that will likely leave incumbency in the skid marks of scorched earth once the journey is complete.

But the moment would be lost if some important observations were not made.

The most important one being that this year it's the liberal Republican's turn to hold his/her nose and vote for the lesser of "two evils" in the general elections seven weeks from now.

For far too many years conservatives within the Republican party have been lectured to time and again by party officials, talk show hosts, syndicated columnists, et al that conservatives had to perform their wifely duties as it related to voting for the choices left for them in general elections. For conservatives these have been bitter pills to swallow for the liberal republicans have far too often been far too similar to the liberal democrats they opposed to generate any real excitement about the distinction of their candidacy.

In election cycle after election cycle conservatives in northeastern states and along the Atlantic coast have had fingers wagged in our faces and been told to accept the fact that reelecting and putting up with candidates like Mike Castle in Delaware was somehow better than electing a Democrat. But after we'd sent them back to Washington we would watch as those same Republicans, the Susan Collins, the Olympia Snowes, the Arlen Specters of the world would proceed to vote for programs and spending that a Democrat would have voted for anyway.

And in Mike Castle's case he committed the most unpardonable sin of all  with the votes he cast in the House of Representatives: he voted in favor of President Obama's cap-and-trade legislation. That piece of legislation never saw the light of day in the Senate once Scott Brown became a U.S. Senator replacing Ted Kennedy. Had it been passed, however, it would have exacted the harshest round of tax increases on the businesses of America, and that would've had a punitive effect across the board on every American citizen in need of goods, products, and services.

Mike Castle deserved to lose in a Republican primary because he voted as a Democrat, end of story.

Yet, still something more needs to be said. For if Mike Castle truly believes in the cause of his party, and if The National Review, The Weekly Standard, Hugh Hewitt, Michael Medved, The National Republican Senatorial Committee (NRSC), Charles Krauthammer and the other voices who consistently call for "big-tentism," are to be believed and if the Bill Buckley principle holds true, then everyone that even leans Republican should be trying to do all they can to help O'Donnell win in November. She has a tough general election fight in front of her.

It is unacceptable -- and will not be tolerated -- if the rumors that the NRSC is planning to withhold resources from O'Donnell to help her close the race in Delaware turn out to be true.

Mike Castle, if he is a man of loyalty to the party he wished to represent should hold fundraisers for O'Donnell beginning next week. Lisa Murkowski should follow suit in Alaska for Joel Miller. And Sue Bowden should be doing the same for Sharron Angle in Nevada.

In other words if "establishment" candidates are willing to give anything more than lip service to the party they wished to represent, then they should be willing to roll up their sleeves and do the hard work of campaigning for someone they disagree with on issues. And they should do so remembering they are in it for the greater good.

The problem, at least on the GOP side of the equation, is that so many "establishment candidates" did not/do not wish to hold to the platform of their party. There is a platform adopted by the party for specific reasons. It gets re-drafted every presidential election cycle. And in the GOP it has been candidates who did not hold to the ideas of lower taxes, pro-life, pro-marriage, gun ownership rights, and strong national security that have been causing the problems for Republicans nationally. And for the same length of time, conscientious conservatives have been told to grin and bear it.

We were told that in the end having a majority with an (R) after their name was the best thing of all.
Well I see no reason why that statement can't hold true when a genuine Republican conservative wins a primary.

If Mike Castle really was polling 11 points ahead of the Democratic candidate for the U.S. Senate seat in Delaware (formerly held by Joe Biden) then it is important that Mr. Castle uses his popularity in that state to raise money and awareness among voters about why Christine O'Donnell will cast better votes for the people of Delaware than the Obama-supporting Democratic opponent would. He should leverage his platform for the good of the cause, even if he feels he has to hold his nose to do it.

If he is a team player, it's what he's got to do...

Kevin McCullough is the nationally syndicated host of "The Kevin McCullough Show" weekdays (7-9am EST) & "Baldwin/McCullough Radio" Saturdays (9-11pm EST) on 215 stations & Sirius/XM. His new book from Thomas Nelson Publishers, "No He Can't" hits streets March 2011.

Fox News Opinion is on Twitter. Follow us @fxnopinion.