Go Along Doggies

Why would the Republican Speaker of the US House of Representatives John Boehner not use his clout to block gun control legislation in the way that Sam Rayburn and later Thomas P. (Tip) O'Neill blocked initiatives they disagreed with from ever reaching the House floor? How come a GOP majority in Congress never seems to be able to accomplish as much as the Democrats do when they are in control or even block what the GOP's most loyal conservative supporters find outrageous? Is it because most of Republican politicians want to get along with their Democrat colleagues and stay out of the way of flack coming at them from the mainstream press or because they never were sincere about being conservative when they ran to the right in primaries or in conservative areas of America, in general elections, or do the current crop of Republican Congressmen generally just have no backbone?