Complex issue, but in short:
As everybody might know we have a serious rift in the Thai society since approx. 2005 (the roots of the conflict reach back much longer, read about the 1973, 1976 and 1992 unrests in Thailand). Simplified there are 2 major groups, the red shirt movement supporting the ex-PM Thaksin with his PT party on one side, and the old establishment / old elite on the other side (represented by the ruling coalition). The red side has won the last 3 elections (2001, 2005, 2007) but was stripped off the power two times afterwards with highly questionable means (one coup, another time through buying MPs and coalition partners for the DP, which is basically the party representing the old elites interests). The actual demographic structure of the Thai population and the unjustly distribution of Thailands wealth between the rich and the poor makes it highly likely that the PT will be the strongest political party in the future.
The old elites have tried with all thinkable (and sometimes highly questionable) means to "modify" the voting behavior of the Thais. Without any success. Again and again the red side wins elections.
Right now hundreds of thousands of websites are blocked here in Thailand, &112 penal code (lèse-majesté law) is used to neutralize political opponents, critical webmasters / writers and even scientists (the latest development). People might believe that Thailand is a democracy with everybody being equal before the law. But that's only the disguise Thailands real power want us to see. In reality there are lots of double standards here in the country, and the real power is held from groups in the background (the old rich families, people from the privy council, the army etc.). The rich become richer, and the poor poorer.
Thaksin and his party was given the chance to rule for four years (2001. 2005) , and this first term was extremely successful. He was reelected with an overwhelming majority even in Bangkok but had then nothing faster to do than to completely mess things up, bringing up corruption to before unknown levels of perfection. Still, he never forgot his voter base from the north / north-east where he remains highly popular. When he reached out to completely take over the power in Thailand (replacing certain army generals with trusted companions) the coup was staged, and he was removed from power. Though there was not much criticism directly after the coup (the Thai people like to live in harmony, and appreciated the series of events / demonstrations in 2006 to end) the people started to understand what had happened in the following months and years: a democratically elected government had been removed from power using the means of the past (18 coups in Thailand since 1932). The awareness of what has happened is much higher now than ever before – and the red movement does quite a good job in teaching their supporters about the Thai history and the misuse of democracy of the past.
Coming to the point: There will be a landslide victory for the reds in the upcoming elections. The old elite has shown in the past that they are not willing to give up the power. The first longer red government ended up in chaos. The coup was a complete failure in the attempt to change the minds of the voters. The policies of the current government also did not convince the people to support the establishment.
Question: What else can the old elite do to stay in power?
This question already creates uncertainty on the capital markets. The outflow of capital from Thailand has started. The THB is falling, growth rate is falling, exports are falling. I expect this trend to strengthen, the old elite will move money out of Thailand, will not reinvest, the only remaining strategy to fight the red movement for the old elite is to hold back any support for the government, to make them fail on their promises of their populist policies, to cap growth, tax income, create unemployment, pressure on wages etc. Etc. . Foreign investors will not jump in under this circumstances, China is close and is also attracting investments.
On the political stage all legal means will be used to remove the red government from power. There is a possible legal case (wrong statements in court) against Yingluck (PM candidate PT and sister from Thailand) , which might be used to take her out. Jatuporn (a great PT agitator) was neutralized already (sitting in a prison he cannot vote, and if he does not vote in the election he is not allowed to be elected, so he will not be able to take on his mandate). We will see lots of more cases like this. Then there is fear in the administration that a red government might take revenge for what was done to them in the past (91 people shot during the demonstrations last year etc. Etc.). A discussion about a possible amnesty for politicians banned in the past started already, but heat will come up once an amnesty for Thaksin will be discussed.
To sum it up: The reds will win the elections in a landslide. They red government will afterwards be involved in endless defensive actions initiated by the old elite. Falling tax income and growth will cause problems in fulfilling the high expectations of the voters. Unemployment will rise, and the support for the yellow shirts will grow again. The social rift in the society will get bigger, the poor will get poorer and lose their faith in the only movement that has ever tried to support them. Mass demonstrations will follow and finally open the door for the next political or military coup.