Is There A Difference In Political Ideology?

Can there be a difference in political ideology? As one tries to understand a concept politically of moderation in the Republican party, I am personally lost as to what former General Colin Powell is trying to tell us. He wishes for Republicans to reach out to a view of moderation yet he does not endorse a Republican moderate such as John McCain who was the Republican candidate for President. He choose to endorse a liberal with no experience who also happened to be a Democrat. He claims he still is a Republican. Why? His views and new founded political ideology seem to be opportunistic and more in line with the Democrats. Thus in my view he is now a Democrat and should be embraced by that party and leave the Republicans.
In theory there can be more than two views represented by both the Democrats and Republicans. Two parties who have the same political ideology create one party rule which we now see in Washington. Mr. Specter proved that point of political opportunism and is a great candidate to be voted out of office.
Republicans in many cases believe in conservative principles such as smaller government, lower taxes, personal responsibility, self sufficiency, small business development, the basic laws of supply and demand which run capitalism, personal wealth formation and most importantly freedom. I personally do not see any of those ideologies embraced by the Democratic party. The Democratic party in America today seems to have a great hatred of our country and is only concerned with an ideology of political self interest and gain by any means. It is an ideology that is skewed and will ultimately lead our country to ruin. The Republican party has the ability to lead our nation to greatness again. The question is will they be ready to lead as they take a new majority in Congress in 2010? With conservative values and principles they can.