We are going to begin from Republican Party websites and Mitt Romney because of according rumors he spent more money promoting his site than anyone else.

 Mitt Romney

• Website designers use relative URL (“/subcategory) for on page internal linking. Even SEO beginner should know that full URL is better to rank well on search engines.
• Problems with RSS feed subscription. 404 mistake.

 John McCain:

• Most news pages were made with search engine unfriendly URL’s. Tails like /4a3ab6fe-b025-42b1-815b-13c696a61908.htm are visible on news, press releases, calendar, and other pages.
• RSS feeds show full stories instead of summary. Many social sites and news readers ping John McCain RSS feeds and show full content on their pages. From one side it creates duplicate content; from another side people are able to read full stories on other networks without clicking “read more” link 

 Mike Huckabee:

• The worst URL structure comparing to other candidate websites. Even important pages do not look friendly for search engines and human eye.
• Hundreds links to other blogs and websites on blog pages.
• Long META tag descriptions. Too many keywords in META keyword descriptions.
• RSS feeds show only titles for each story without summary. Most social networks and news sites don’t accept sites with this RSS structure.
• URL canonization issues on every page.

 Rudy Giuliani:

• It was hard to find SEO mistakes on Rudy website. The only mistake is relative URL (“/subcategory) for on page internal linking.

Democratic Party

Hillary Clinton:

• Mistake on a weblog. Every blog post contains clickable title which leads to the same page. When search engines crawl website they don’t see actual title and follow it as link to the same page.
• Website contains useless subfolders like /blog/view/ instead of just /blog/. This situation hurt URL structure which look unfriendly to search engines and human eye.
  Relative URL (“/subcategory) for on page internal linking.
• Someone was little lazy to organize news into folders. Many news pages show over 200+ links to recent news and articles. 

John Edwards:

• The same mistake like on John McCain website… RSS feeds show full stories instead of summary.
• Duplicate content appear on different networks which read RSS feeds. 

  
Barack Obama:

• The same META tags for many pages.
• Many subfolders were used to build a website.
• Canonization issues