Shanna Pearson-Merkowitz and John McTague break down the votes of every Senator by faith since 1976 along ideological lines. They then plotted those votes along the ideological spectrum, where -1 is the most liberal while score of +1 is the most conservative. As you can see by the chart below, Mormons are more conservatve than even Evangelical Christian Senators.
Since 1976, Mormons average 0.21, firmly to the right of the moderate center point of zero. If you add the records of all other senators over this timespan together and average them, the number is -0.03, or just a tick to the left of center. If we restrict our analysis just to the Republican Party, we find that Mormons are a few notches to the right of their peers, registering an ideology score of 0.36, versus 0.31 for all other Republicans. Compare this with Republican evangelical Christian senators’ score of 0.42 and there is ample evidence of common ground between the two religious groupings. If religion were to influence a future Romney administration in the same manner as it has Mormon members of the Senate, then we should expect Romney to pursue a consistently conservative policy agenda, more or less in line with evangelicals.
Among Republicans only, Mormons still outflank their colleagues, voting conservatively, on average, 94 percent of the time, compared with 73 percent for all other Republicans. Republican evangelical Christian senators voted conservatively 92 percent of the time on these issues, nearly identical but slightly less than their Mormon co-partisans.