Thanks to President Obama, a number of long-disputed conservative assertions have gained a whole lot of traction. Experience under this president should be instructive on a number of points:

U.S. Secretary of State John Kerry, left, meets Palestinian President Mahmoud Abbas in the West Bank city of Ramallah, Thursday, Dec. 12, 2013. Kerry has been shuttling this week among Israel, the Palestinian territories and Jordan in a frantic bid to get the peace negotiations back on track amid rising public anger among Palestinians over Israeli settlement activity and among Israelis over the release of Palestinian prisoners. (AP Photo/Brian Snyder, Pool) Secretary of State John Kerry, left, meets Palestinian President Mahmoud Abbas in the West Bank city of Ramallah in December.(Brian Snyder/Associated Press)

1. If the United States recedes from the world, things spin out of control and despots flourish.
2. It’s not the NLRB rules, but the nature of unions that causes them to lose elections.
3. The Palestinians are the hold-up in the ‘peace process’ because they won’t give up the aim of eradicating the Jewish state.
4. Keynesian economics as exemplified in the stimulus bill is unlikely to work, in part because by the time people get into jobs (“shovel ready jobs”) it’s too late to boost the economy.
5. Federalized, compulsory health care doesn’t work. Government can be too big to succeed.
6. Cutting discretionary spending doesn’t do much at all to curtail the debt, which is driven by entitlements.
7. Cutting defense spending doesn’t do much at all to curtail the debt, which is driven by entitlements.
8.  When the president ignores human rights the plight of dissidents and repression get worse, as we’ve seen in China, Russia and Iran.
9.  Telegenic campaigners can lack governing skills. (Need we say more?)
10. Radical environmentalists will ignore inconvenient truths to maintain battles against environmentally safe energy projects (e.g. the Keystone XL pipeline).

Republicans in the last five or so years should have learned a few things as well from their own failures:

11.  It is getting harder and harder to win national elections without a significant share of nonwhite voters.
12. Voters don’t like government dysfunction and equate it with indifference to their needs, as we learned in the 2013 shutdown.
13.  Voters will reject extreme, verbally undisciplined candidates even if the Democrat’s record is shaky, as we learned in Senate races in Nevada, Colorado, Delaware, Alaska, Indiana and elsewhere.
14.  Attacking fellow Republicans doesn’t make Democrats more compliant as we saw in every stand-off since Obama took office (e.g. defeat of Plan B on the fiscal cliff, defunding Obamacare, the Budget Control Act of 2011).
15.  Voters may want reform, but they don’t want to rip out the safety net.
16. Americans love hardworking immigrants, as virtually every independent poll shows.

These truisms, amplified by experience, won’t keep liberals from proposing Keynesian stimulus plans or right wingers from putting forward radical and untested candidates. It does however make it easier to predict the consequences of  policy or political decisions. It therefore should come as no surprise that Russia and Syrian President Bashar al-Assad have made  a peace deal impossible in Syria (#1) or that tea party radicals trail mainstream Senate Republicans by huge margins (#13). You can bet voters will be furious about a government shutdown or debt ceiling impasse (#12), just like you can predict there will be many more defeats for the UAW. (#2). No matter how sophisticated your Web site (#5) structural problems (e.g. young people signups, disincentives to work, unavailability of doctors) swamp the best of intentions (e.g. universal access to affordable health care).

Certainly, unique circumstances produce unexpected results, but doing the same thing over and over again (e.g.” the peace process”) and expecting a different result (#3) is, if not insanity, generally a losing proposition. Maybe, though, we can warn off politicians with a new shorthand: “Hey, Senator Cruz — that’s a #12″ or “Save the flying time, Mr. Kerry, you’re pulling a #3!” At any rate, it would be helpful if politicians would use some short-term memory in deciding their next move.

Jennifer Rubin writes the Right Turn blog for The Post, offering reported opinion from a conservative perspective.