A head to head comparison of the Utah 2012 General Election gives us an idea of the break down of the voters.    

Mitt Romney received 671,747 (74.5%) votes, beating Barack Obama who gained 229,463 (25.5%) by 442,284 votes in Utah.

Mitt Romney won all of the 29 counties whereas Barack Obama won 0 counties in the State of Utah.

Presidential General Elections

During the 2012 General elections, over 122M total number of votes were cast. Barack Obama got 62,614,654 (62.6 Million) over Mitt Romney's 59,141,654 (59.1 Million). He won the popular vote by 3,472,979 (3.4 Million). Even though he lost to Mitt Romney in the State of Utah, his 229,463 gained votes represent 0.4% of his popular vote victory. The remaining 49 states contributed to the remaining 99.6% popular votes victory.

Top 15 Counties in Primary Elections vs General Elections

All Candidates (General Elections)

These 15 counties play an important role in these Primary elections. If a candidate, can get a sizable majority in the larger counties (Salt Lake, Utah, Davis, Weber),  it becomes very difficult to win majorities in the smaller counties without voter outreach and increased voter participation in them.

Top 15 Counties Comparison in Primary Elections vs General Elections

General Elections
Barack Obama

General Elections
Mitt Romney

Salt Lake, Utah, Davis and Weber, four of the larger counties, voted in favor of Mitt Romney giving him a 293k vote advantage. However, Mitt Romney's steady win in all of the counties made him gain an upper hand in the State of Utah.

Related References: 2016 Utah Primary Election Story, 2016 Utah General Election Story, 2020 Utah Primary Election Story, 2020 Utah General Election Story